A couple of posts ago i mentioned the brake problems i was having
since then i have gotten told i need to replace the master cylinder and i bought that but im perplexed as to how to go bout installin it
im puzzled by the haynes manual because of the lack of good diagrams any ideas on how to install it would be great

You should be able to follow the procedure in the book, If you don't feel confident doing this perhaps you should let a professional do it. Brakes are not something to take chances with. That said, a few basic tips;
1.Make sure all your bleeder valves are unstuck before you start. You may have to spray them and let them sit overnight. 2.If a bleeder valve is stripped you may have to use a vise grips to get it out and replace it with a new one.(not an expnsive part.) 3.Bench bleed master cylinder before installing it.(follow the directions in the book.) 4.Always use a line wrench on line fittings. (or you could egg shape them and cause a leak.)5.Dont let the master cylinder run dry when bleeding the brakes. 6.Change enough of the fluid untill it runs clear, you want all new fluid in the system. I would gravity bleed the system first, then find an assistant to pump the brake pedal for you. Hope this helps.

I did the same on the 91 I got. Just bleed the new cyc the way it shows in the material that comes with the new part and put it on. 2 bolts hold it on if I remember right. Less than a hour work. $25 part cost. gl P.S. MAKE SURE YOU GET THE MASTERCYC BLEEDING INSTRUCTIONS WITH NEW PART.

Forgot to mention I did not have to bleed at brakes after install. Make sure you bleed master before install real good. No more seeing air bubbles.

did u have to dump the fluid out of the reservoir or did u just drain it when u unhooked the hoses

Dumped, leave the cover on the old one when taking off.

I got it off in 10 minutes no problems made an evironmental hazard on the road when i dumped the fluid out the old cylinder onto the road bolted new one only one problem the first bolt for the brake line i had to give it some persuasion put her in filled er up got em bled run the best ever no squeaks like i have been having for 5 months after i replaced pads twice so thanks again guys im happy as this problem has been resolved