How to clean up my build plate for a new build surface? My ender3 came with a BuildTak-clone surface, and as I was a little too vigorous in getting the print off the bed (I had failed to level right and printed a bit too tight to the bed, resulting in SUPER strong adhesion), I needed to replace it.

Peeling off the black was easy. The plastic sheet that held the glue was easy too... but how to clean up the bed to get the residue glue off and prepare for the new 3M sticker?
In my experience, we deal with 3M™ Adhesive Transfer Tape 468MP; high-temperature glue residue. To remove the leftover glue from my Aluminium build plate I found that it works best if I apply paint thinner. 

I ran out of acetone for one refurbishment so I tried thinner and white (cleaning) spirit; the latter option did not work well. However, thinner worked very well. I got a bottle of "thinner" at the hardware store's house brand and found it to be more aggressive stuff than turpentine or acetone. I had tried those latter 2 but found that "thinner" works best.

Putting the thinner fluid on paper cloth directly to clean the glue did not work well. I applied the thinner directly onto the glue (splash it on), waited for a while to let it soak in to weaken the bonds after which you can remove it with a spatula and kitchen paper towel.

The exact contents of paint thinners are not always available but they contain various hydrocarbons.