how to? remove/add surface to .m2

[beskytter makt]

looking for somewhat easy way to edit the shape of models,
and would it requier MEF?

ive seen the guide with the bear and its "LAWL" forehead
i tried using that program (think its trial or buy) but i couldnt get the hang of it
before trial end, and its not realy a beginer friendly experiance,
if theres an easier one please let me know

(prefer one thats "free/unlimited" rather than trials or buying)

also can you "fuse" m2 or blps, cut and paste style?

say to take a gun then cut barrel short take the stock add an axe head to it and reanimate to a pistol (kinda like a gun from darkwatch)
(not gona do that btw jus example, idea is free to take given its not already been done)