Need instructions to replace keyboard on my toshiba satellite A135-s4427 notebook

You can download it here for free:

http://www.manualowl.com/p/Toshiba/Satellite-A135-S4427/Manual/165450

Go to toshiba website:http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=DL&os=&category=&moid=1598555&rpn=PSAD0U&modelFilter=A135-S4427&selCategory=2756709&selFamily=1073768663

All available drivers for your laptops model can be found here : http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=SB&os=&category=&moid=1598555&rpn=PSAD0U&modelFilter=A135-S4427&selCategory=2756709&selFamily=1073768663
hope this was helpful.

do a search about "screen replacement" or "laptop repair" in youtube. I've seen many videos about computer repair in there

Try the following link

http://www.irisvista.com/tech/laptops/toshiba-satellite-a135/remove-mainboard-1.htm

the ram memory must be sufficient about 2GB & the processor must be dual core or core 2 duo.
if both condition your laptop follow then i think you should scan your lap top with anti virus.

replace the lcd

The Toshiba Satellite A135 series stock keyboard is not backlit, and that model only supports one type of non-backlit keyboard, which is interchangeable with several other Satellite series. Here is some extended info on the keyboard for your model: http://www.machinaelectronics.com/store/buypart/Toshiba_Satellite_A135_S4427/K000044100

Check out this link for XP drivers http://support.toshiba-tro.de/tools/Satellite/sl30/xp/display-psl30e-xp-820300.zip

when you connect the AC charger with the battery , your laptop power on ?
and try to directly connect the ac charger with laptop without the battery, if it is on, that means the battery go bad, you need replace