pool liner problem

My pool liner has pulled out of the bead channel and has a horizontal tear 2-3 inches below the bead about 6 feet long. Liner is about 7 yrs old. A leak at one of the pool lights caused the water level to drop over the winter. I did not repair and just left the water level low. This caused the liner to come out of the bead channel in one corner and tear. I have repaired the leak and am now considering how to repair the tear and get the liner back in the channel. The tear is about 6 feet long but very wide since the liner has shrunk somewhat. I have vinyl cement and a large piece of liner that matches the top, but the bead is flat instead of rounded as the old liner bead has become. I have put the bead back in the channel but it will not stay by itself. I want to attempt to install the new piece of liner over the old and put the flat bead over the old bead. The liner below the tear is about 10 inches out from the pool wall. I believe fill the pool somewhat and force the liner back against the wall. Is that right? I then will put the new liner piece into the channel over the old bead and continue to push the old liner against the wall. Eventually I hope to be able to cement the new piece to the old for the completion. May have to use some kind of clips in the channel to hold the liners but doubt it as the new bead is extremely hart to put in now. Any suggestions will be appreciated.