Thanks for the tip.
I did some reading about it and as you say it actually seems quite simple to do.
Do you know any onlineshop with all stuff (reflector, lens, bulb, and the batteryholder)?
I´m in Europe and would rather not pay multiple shipping from different places.
I checked on lighthound but couldnt "only" find the lens and the bulb.
It's very simple to do. I've put together a couple of them and I have ZERO skill when it comes to modding flashlights.
It's going to be pretty difficult to find one website or person who has all of the needed items, so you are most likely going to have to pay a little extra for shipping since you live in Europe.
If you really want to use that 2D Mag of yours then the 2D ROP High is by far the best option. The thing is that the actual Maglite is a pretty small percentage of your cost for building one of these, so if you are willing to buy another Mag then you would have quite a few more options. I recently built a 4C Mag85. I personally think it is one of the best hotwire lights out there, and also one of the most affordable. Here is everything you need to buy to make one, and where to buy it:
4C Maglite (Zbattery.com) = $22 Shipped
Cammed Aluminum Reflector (Kaidomain.com) = $15.00 shipped
Borofloat Lens 52.1mm x 2.0mm (Flashlightlens.com) = $6.25 Shipped
Potted WA 1185 Bulbs (Litho123 in CPFM) = $8 Each Shipped
3x New AW Nipple Top Protected 18650 (AW in CPFM) $12 Each Shipped
PVC Tubing To Hold Cells In Place (Lowe's/Home Depot) = Unsure Of Cost, but should only be a buck or two. Make sure to buy one that fits protected 18650 cells nicely and is snug inside of a C cell Maglite.
Ultra Fire 139 Charger (AW in CPFM) = $15 Shipped
You can also buy your glass lens at Kaidomain.com if you want to cut back on shipping charges. Make sure to buy one that is 52.1mm x 2.0mm, as that is the correct size for a Maglite head. The whole thing is going to cost you *at least* $100+, so if you aren't willing to spend that type of money I wouldn't really bother. I consider this a true budget hotwire, as most hotwire lights would run you quite a bit more than this. Mostly because they use expensive battery carriers, or use a much more expensive charger. While this specific light doesn't use a battery carrier at all, and the charger for it only costs $15.
If you've never seen a hotwire before prepare to be impressed! Here is a thread I made comparing my Mag85 to a set of car headlights:
http://candlepowerforums.com/vb/showthread.php?t=190451
Considering that the Mag85 is only one light and the car headlights are two, I think the Mag85 held up pretty well! I would definitely say it is brighter than one car headlight.
If you need anymore help don't hesitate to ask.