Before replacing printing sheet for your 3D printer, you will need to peel off the old printing sheet, remember to remove all the residue double sided tape on the build platform before applying the new one.
It is important to have a clean build platform, if you applying straight on the residue double sided tape, the bed will be uneven and causing leveling issue.
Some user use WD40 or ronsonol oil to clean it, I prefer to scrab it off bit by bit, it maybe a stupid and time consuming way, but I can ensure that no oil will left on the build platform and affect the adhesion of the new printing sheet.
This is how I removing double sided tape from 3D printer build platform. Not the way but my way. Let me know how you do it.