It's pretty hard, because this is the value encoded in hexadecimal form. You now need to find the value that is responsible for this counter. So, let's say that, having done all the actions above, you pump up to the 40th level and counter to your experience at the moment 0/2000.
Just click twice on the desired value from the list found, that it appeared in the lower window of Cheat Engine and leave it for the moment alone. It's the need to change (in this case lower), BUT it is not necessary to do this now. Will be somewhere in the 6-8 values in the list. Filter out values with the new values of the level. Using the console command setlevel(*) increase the level by one. After the first search displays a huge number of values. See what your level is, to drive that number in Cheat Engine (value type - 4 bytes). In General, as already mentioned Igor_Kholupko must first poshamanit with the level using Cheat Engine and in-game console. To lower the level without any casualties as possible.