Screwdriver, stanley knife, cable ties, alternative internet access, time.
The big reason why things are much easier now than they were when I first started mucking about inside PCs (a very long time ago) is that we now have wifi and devices which connect to it. It used to be the case that there was only dial-up or broadband connected directly to the only internet capable device in the house, which you had in bits. Because of that I always felt I rushed to get it finished, and when things didn't work there was nowhere to turn. Now if it falls down I have 2 other PCs, a laptop and a phone to turn to.