ive heard there's another way to open them other than cutting, but nothing that ive found. all the sets i do, i just cut them open carefully...

 

Watch the video how to open E60 headlights. I got inspired by it and opened headlights successfully.
BMW E60 E61 Scheinwerfer öffnen open headlights - YouTube

 

I've done this before but not to E60 headlights, I guess it could be done, I like how clean it comes off.

 

It can be done. But its a lot of work.

 

What did you seal wit back up with? That looked almost TOO easy. Also how long did it take you to get the light open?

 

I used a black aquarium silicone for sealing. Opening the headlight took about one hour.
Opened and resealed headlight:

 

Looks good, everything sealed properly?.... Did you just apply heat and pry like the video above? Seems worth the time instead of cutting....

 

Everything is sealed properly, I tested it with air pressure with blocked breather elbows.
Yes, I was applying heat and then very hard pry polycarbonate part out (i needed to use much force to open it). After opening, the flange on black plastic could be damaged so I repaired it and cleaned the flange from old sealant (it was hard work to remove the sealant).

 

Gotcha, great job once again... Is most of the work at the bottom? dont really have a visual since Im not actually looking at a light. To seal you basically apply the sealant to the channel on the housing and clamp the lens and light together right?

 

I just simply filled groove around housing (whole old sealant removed) with silicone to about 2/3 of height, pushed transparent plastic part into the groove and wiped out silicone from outer side with wet finger.