You can clearly see there are four pieces of Plastic cards. In the kit there are only two. what would help would be a plastic card that is at least three times longer, so that it can be pressed bellow the battery.
I’ve started with iOpener but changed very quickly to a heatgun. That was more efficient.
T3.15A250V fuse and you can get it on Ebay, Alibaba, Aliexpress and maybe Amazon.