This particular subject has been discussed repeatedly here and, in addition to the wiki, there is a lot of information about this in these forum threads.
Google also has some useful guides on installing this, and related things, on Dreamhost
You haven't indicated what problem you encountered in trying to follow the wiki instructions, so it's kinda hard to tell why you "are not able to install it" on your server. Where does the installation process fail, and what error message(s) are you getting?
If you have read through those threads I linked, you will find a couple of guys that have offered to help with this if you just can't do it yourself (but you may find the help you need in those threads).
If not, maybe if you post back here with a more complete description of what you have tried and what trouble you are having, some wizard here will have a better chance of being able to help you.