ow to open caseing of bosh psh32g hedge trimmer?

You will have cut the cable while using the trimmer - easily done.

Cases are usually held together with Torx (security) screws to prevent casual dismantling. My guess is that you used a crosspoint screwdriver and failed to loosen any screws.

You can buy or borrow a Torx driver set or you can fit a two pin cable joiner - very cheap from Amazon or a hobby electronics shop.

Good Luck...
September 2015