Pairing Apple Watch when Required update won't let it.

How do I pair an Apple Watch when it isn't connected to the internet but a software update is required. How do I get rid of the software update so I can pair first?

My watch is a series 3 and when I went to do the update, it said there wasn't enough space. I reset to factory setting which was a mistake because now it isn't paired and when I try to pair it, it says I have to do the update first, but that doesn't work because my watch isn't connected to WiFi because it was reset.