ok guys i have a problem with my router i dont know if you guys can help me or not

ok so i got a new router a cisco 877w is a very very nice router worth like 500 dollars
luckily i got it for free but it has a been a pain to install it
I have no freaking idea how to install it because first i dont have the documentation for the router 2nd i dont have any software for it and 3rd to add to the complications its a business router so the set up might be a little different than a typical home router

i was kind of hoping to see if you guys could help me with it getting any info or to see if you guys have installed a businnes router before

any help is appreciated