AG liner installation is not one of my areas of expertise. Here's the best I can offer:

1. Search Youtube for a helpful video, using the search phrase 'above ground liner install' -- but be careful, there are a lot of idiots on YT. These 2 vids looked promising, but I didn't watch but a few seconds:
https://www.youtube.com/watch?v=nmJIRMh4CV8
https://www.youtube.com/watch?v=oM3SGtFssQc

2. Check the liner companies for installation guides. Here's a Doughboy guide: www.pools.com/doc_library/docs/Liner installation.pdf

3. If you find some thing helpful, please post those links back here. Thanks!

4. Good luck!