I’d like to update a Microgranny Bastl 2.0 version to the 2.5 version, is it difficult? I can screw and unscrew but I cannot weld nor program.
There are no instructions on the site, can somebody tell me if someone had done it?

The ic chip you upgrade is slotted so you can unscrew the case and then pull it from the board. You do need a device for reprogramming chips or you could buy a preprogrammed upgrade chip from bastl. Not sure if bastl still has the upgrade chip listed as a product but they would almost certainly sell you one if you asked.