Get some clamps, clamp the visor down, and then put the goop glue around the edge. Overdoing the glue is fine!
Do the bottom part of the T first, and then for the two left and right visor parts, use something to keep them in place as you hold them down. I wedged a pipe inside of the bucket to keep the visor down. I also used a towel inbetween the visor and the pipe to make it so it will not scratch.