you absolutely positively CANNOT REMOVE the platters from a multiplatter drive without a special compression tool! 

if its a single platter, your ok. I disassembled my 80MB all the way removing the platter and fixing it. its rocking in my classic right now. 

Also when you remove the headstack, you must make a jig to hold and keep the two heads apart when sliding them off the platter. you CANNOT let them touch EVER! it can knock one, or the other head slightly out of alignment with one another. this will cause a cylinder mis-alignment and the drive will never function again.