This is a step by step install or upgrade to the older MES 800 watt heating element to the new MES 1200 watt heating element.
With little modification I was able to accomplish this. I am hoping this will fix the heat recovery time on the MES when the door is opened.
Before doing this MOD i would suggest doing a wire upgrade. Masterbuilt is still using the 16 gauge wire on all there MES's so apparently there not to concerned with the old wiring problems they where having.
The new 1200 watt heating element kit includes 2 replacement wire with connectors. It is very cheep to do the wiring upgrade i did mine for 30 dollars.

(STEP 1) You will need to call Masterbuilt and order a new 1200 heating element kit.
This is what you will get in the kit One replacement element, 1 gasket, 2 replacement wire Assembly's, 2 wire nuts, 2 element screws, 1 grounding bolt and nut, 1 replacement instructions.

This is a pic of the different heating elements side by side

This is a pic of the back of the elements virtually identical. The new 1200 watt element on top in this pic has threaded screw holes if you look closely you can see them in the upper element.

(STEP 2) Remove the woodchip loader from the unit.
(STEP 3) Remove the drip pan and woodchip tray from the unit.
(STEP 4) Open your mes and remove the 2 Phillips head screws on the left hand side of the woodchip housing support.

(STEP 5) Remove the 2 Phillips head screws from the right and side of the unit on the woodchip housing support.
Note: These can be harder to get to if you have a long handle Phillips screw driver it may help. If not you can slightly bend the woodchip housing to get to them.
(STEP 6) Remove the 2 Phillips head screws from the upper woodchip housing and remove the housing. Be carefully this can be tricky you will have to bend the rear of the housing a little to get to the unit over the heating element.
You can see this in the next this pic.

(STEP 7) Remove the 2 Phillips head screws from the heating element on the back of the unit.

(STEP 8) On the back of the unit. remove the drip pan and the 2 drip pan support brackets with 4 Phillips head screws. On the back of the unit there is 28 rivets holding the back cover on these will have to be drilled out to access the wiring to the heating element.

(STEP 9) Remove the electronic control board bracket screws on the back of the unit.

(STEP 10) Push the electronic control board to the rear of the unit to get access to the wire connectors under it. Remove the 2 mo-lex wire connectors that go to the electronic control board.

This is the back of the unit with the cover off. The lower electrical box needs to be removed to access the wiring.

(STEP 11) Use a 1/4 wrench or socket to remove the nut and ring connector on the ground wire. You can put your hand threw the chip loading tray and use a Phillips screwdriver to hold the head side of this bolt if your having trouble removing this bolt.
(STEP 12) Disconnect the 2 push wire connectors to the heating element. You will have to move it to the side and pull the wiring out threw the hole on the right side.
Be carefully not to cut the rubber grommet you will need this to reinstall the wiring.

(STEP 13) On the back of the electrical box make a transfer of the holes from replacement gasket supplied by Masterbuilt.

(STEP 14) Drill out the holes for the heating element and support screws. I used a 7/32 drill bit and a 3/8 for the larger holes. Bend the old screw taps out of the way.

(STEP 15) You will have to drill out the holes where the old heating element attached to the back of the unit so the new screws will fit threw the back of the unit. Install the new heating element and seal in the unit from the inside. Install the electrical box you drilled out on the back of the unit.Reinstall the new supplied ground bolt and nut to the ground wire ring connector.

(STEP 16) Reinstall the back cover with sheet metal screws. reinstall the electrical control panel. reinstall the complete woodchip smoker housing on the inside of the unit.

These last 4 pics are scanned images of the instruction manual masterbuilt sent with the new heating element you can follow them to help with the MOD