I would use Kapton tape instead if there is already a heated bed.
I got one of these thin and highly flexible wall scrapers / spatulas.
Ony 2$ or so and sharpened ONE side so it looks like a chisel.
Removed the edge with some fine sand paper so it it dull.
Push under the part and do slight movements from left to right - the "blade" will work it's way under and after a few cm the part usually pops off.
But with a lot of trouble getting parts off it might be a good idea to set the Z endstop a tiny bit higher.
You want is so that the first layer is not pressed into the tape but spread on it like butter.
Especially big parts can be a pain and sometimes it helps to put the bed with the part in the freezer for an hour.
The difference in expansion lift the part from the tape - but this works best with Kapton tape or when printing directly onto the glass.
