There are multiple methods for debonding 3M™ VHB™ Tape adhered substrates. The method and tools/techniques really depend on the application and substrates. For mobile phone rework, heating nozzles are used to heat up the top surface of the substrate and then a suction cup to lift and remove the substrate. Keep in mind the tape on a mobile phone is usually not very wide so the amount of required force to cleave the tape at an elevated temperature is not that great. Depending on how wide the tape application area is, this may or may not be your best route.
For large bonded panels, reciprocating tools with a flat blade work well to cut through the tape. Heat is usually not used on such large panels, but it’s important to lubricate the blade when cutting through the tape.
For the application you described, I’d suggest the heat and suction methods. A small prying tool also helps to separate the two substrates when using this technique. I have attached a flyer for full substrate removal and some of the tools used for it as well as a video describing removal on an industrial panel application. Please let us know if we can answer anything else.