How to cut a cilinder at a 45degree angle in the middle?

I have a model of a hollow cilinder as a part in Solid works.

I want to cut the cilinder at a angle of 45 degrees in the middle(cut in length direction).

I am trying to by getting

a plane in the middle of the cilinder, under a 45 degree angle, but what i've done till

this point did not work.

If I know how to get the above done with two of the same cilinders, it is possible to mate the angular sides to each other,

therby the end result will be two cilinders making a 90 degree corner/fit.

Hopefully someone will read this and can give some hints/advice.

Appreciate it!

Best regards, Jeroen

SolidworksParts And Features