The key to the process in my opinion:
1. Keep as much of the mylar under uniform tension as possible without trying to lift it yourself.
2. Let the chemical you are using do its job in lifting the mylar
3. Having the playfield on a slope and slant to allow your chemical to pool around the lifting mylar area helps greatly
4. take your time and if you find you are getting tired or impatient - stop and come back tomorrow
Hope this helps someone out there. Thanks for listening