Wow, I just looked at that chinese site to see what this rubber stuff is. What a PITA! All that driving around to calculator repair shops, measuring with metric rulers, and cutting and then this: "first uses the cotton and kapok bamboo slip in the installment to..."
Bamboo?
Guys, what are you thinking? Just dip a toothpick in the conductive paint and touch it to the contacts. No super glue, no tape, no bamboo, no cell phones, just a tiny dot of paint on each of the 3 or 4 bridges. Yeah, they're small, but jeez it's really not that tough. If you are in late stage Parkinson's you may need a retry or two - no problem, just wipe with paint thinner and then polish clean with a pencil eraser. You really can do this without bamboo!
fandudeals: There are traces on the top of the processor packaging that are laser cut after assembly. It is your task to re-connect them.