Guys my new tube will arrive today or tomorrow. Can anyone share experience on changing it from the stock one. What do I need to consider / care in the process? Tx
it’'s easy don’t panic, remove old one, place the new one in.
keep the wrapping around as the holder are generally to large for the tube diameter (centred, not too low for 1st mirror). what is important is your tube is parralel to Y axis. with about 2 or 3 cm from the first mirror.
cut a bit of pipe slot it on the wire, round several tours of wire on the tube pins to have a good connection (large enought contact area). cover with the pipe and fill the pipe with silicone ( provided with K40), both side the same, let it cure before fire.
You are done and ready for alignment.
check photos from old post (19/4/2015, 10 nov 2014, I forgot the pipe just a lot of silicone and it work fine, help to hold silicone and reduce chances of arcing)
@StephaneBUISSON how did you now I was panicking? 
Thanks
@StephaneBUISSON how long till the Silicon cures? Tx