proper way to install icewm in 15.04

[zentara]

Hi,
I think Lubuntu15.04 is a great, well performing
distro. I've installed it in a few laptops, and it 
is a better looking install than MSWindows!

I am used to using ICEWM, and am wondering,
what is the correct way to change from LXDE to ICEWM,
taking into account all the various resource files?

I was able to get icewm to run, by putting a local
.xinitrc file in my home directory, with a few lines:
exec /usr/bin/icewmtray &
exec /usr/bin/icewm

But I lost the graphical login, and a few other things.
So what is the proper way to do this?

Thanks,
0m,
zentara