If you have had the keyboard shoot craps on you, the only option is really to replace it. This isn't all that unusual to have happen. I've had keyboard issues with every laptop I've owned, bar my thinkpad made in January '98 (which I still have and use).
If it is still under warranty, I'd recommend hitting up Lenovo, who will recommend a local authorized shop that can replace it. That is what I had to do with my ideapad. I found one around the corner from the university that I went to (was actually within walking distance), I dropped it off, and they swapped out the keyboard and had it back to me a couple days later.
The reason I suggest this if you still have the warranty, is so that you do not void the warranty. Plus, if it is under warranty it won't cost you anything. Lenovo covers parts and labor for upto a year.
If the warranty has expired, then I would recommend hitting up ebay for a replacement. Should be about $30 after shipping (sometimes more some times less). Replacing a laptop keyboard isn't hard, as long as you are patient, pay attention, and keep track of everything. Remember, DO NOT FORCE ANYTHING. If it isn't wanting to come apart easily, then you're doing something wrong.