Couldn't do it in 6.6, updated to 6.7 and it worked. I don't know how to make a CE file for this, but you can do this to edit your XP and meat. Here are my steps:
* Connect to West of Loathing process
* Under "Mono" menu, select "Activate mono features"
* Under "Mono" menu, select "Dissect mono"
* Expand the only item in the list
* Expand "Assembly-CSharp"
* Expand "MPlayer"
* Expand "methods"
* Click on either "AddXP" or "AddMeat" to select it
* Right click it and select "Execute/Invoke method"
* Under the "Instance address" drop down, select the first item
* In the other box, enter how much you want to increase your value by
* Click "OK" <- CE will not show that anything happened, it will look like you clicking "OK" did nothing (no result, no message, nothing) but then go to your game and you will see the value changed.
Note: when I did this, I quit the game afterwards, to see if it does actually save the new value. The program crashed when exiting, but it did save the value. When I went back into the game, the new value was there.