I need to replace my Logic Board and display cables. Please Help!

My mother went to try and power on my Apple 13" MacBook Pro laptop and it wouldn't power on. So, me and her took my laptop to an Apple Store in Orland Square Mall to see if, we could get it fix. To our dismay the technician told us that my computer would be useless unless it was fixed first. He told us that he had to ship it over to China for it to be fixed because, there were no available technicians in the store who could fix it. Then, the guy said it would cost me $755.00 to get my computer fixed because, it had corrosion on its logic board and display cables due to water being spilt in the back of the case. He also told us that if we had gotten a warranty on it when we first brought the computer it could have cost us much less to fix. My mother told me that she was not going to pay that much for a computer to get fixed and that $700 can go on several bills instead and that we would also be better off just buying a whole new PC computer instead. Now, I am here trying to see if, I can't fix my Apple computer myself and save me $700. I know that the logic board and display cables need to be replaced but, I don't know how to or what the right tools are that I need to do so. Is there any guide on here that can help me with an Apple MacBook Pro 13" Mid 2012 Model type laptop Computer??

Also please note that the email: newiformatives@gmail.com or yahoo.com is my mother's email address and is the wrong email address to use to reply back to me with a response to this post. Please respond or reply back to me with your answers to this post at this email address only which is ladytis19@gmail.com not, newinformatives@gmail or yahoo.com.

Thank you!