Can I re-key a lock myself? Or change a full lock? I am a single woman alone...

Or change a full lock? I am a single woman alone and came home tonight to find my door be open. My neighbor across the lobby was horrified and I'm making call to have the locks tuning but I was wondering what it entail to do this on my own?
Answers:    go to True Value or Ace Hardware or Home Depot etc..
and buy contemporary locks. its not that hard to transmutation them.. the locks will cost maybe $20 or more..

but in that are instructions too so dont worry.. im sure the store associates can relieve you too.
You could do it yourself. But their is quite a bit of equipment needed and reasonably a bit of knowledge needed. It is much easier to hold the door knob off beside a screwdriver and take it to a locksmith and hold it re-keyed (around $5). You could spend a little more and hold a locksmith come to your house (around $50). You could also go to Lowe's, Home Depot, or Wal Mart, etc. and purchase a unusual door knob. They come with instructions are pretty straightforward to install.