@Avitt, No tools needed, the tube fits nicely into the case. Only prolem is that the tube is not threaded all the way, so when you are screwing it in it will stop at a stage shown by the pictures where the case has no pushers.
I used force to make the tube screw right in. (T8 + Plyers)
Basicly, when the tube runs out of thread i use pliers to force it right in.
I guess you could use a small grinding stone to remove the first 2-3 threads in the case, that would also solve the problem.