Ok, so I was thinking abut a method to install the visor that could be easy to install and remove without the use of tools or drilling into my visor, some kind of clip on/clip off method, so I was looking for some kind of flat clip that will accommodate the 3mm acrylic of the visor I bought from T-Visor.com but wasn't able to find them, so I had to build my own. So I started with a standard small paper clip 3/4" (19mm) I got at Office Depot, this are really cheap, I don't know in the US, but here are less than a dollar for 12 pieces.
then remove one of the "legs" and flat out one side using some pliers...
I did cut the flat side using a dremmel tool cutting discs to remove the round part that used to hold the "leg" to make it as flat as possible to glue it flush to the edge of the helmet, I used plastic welder 2 part glue and it works like a charm gluing metal to plastic, remember to sand a little bit the plastic part in the helmet to give it a better grip...I installed 3 on top and 4 on the vertical part of the T, I have no problem on the sides of the horizontal part.
I left the remaining leg on the 3 top clips, it makes it a lot easier to slide the visor in and on the vertical part the visor just slides in with no effort at all...
Hope this helps, I'm happy with the result...