I put one in last year and used their free financing for a year too.
It does take some thought on your part. Specifically, getting the dimensions and locations of your windows, electrical, plumbing correct etc.
You download a tool from the Ikea web site and start clicking and dragging their cabinets into your desired locations. Save it and then go to the Ikea Kitchen sales people to check over your design.
I fully promote using one of their Ikea Approved Installers and not going to Craigslist to get a cheaper price! Cost is roughly about $2K and worth it in my book. Demolition and re install took two days only. I would have been doing this myself for weeks . . ..
The Approved Installer (a former Ikea employee) comes to your home and checks your design versus the physical space. Once he checks off on it then you can move ahead with the demolition and installation.
You will need to have a plumber and electrician come in right after the new cabinets are installed. Also if you are doing a custom back splash like I was, you will need a finishing carpenter as well.
Only snag I hit was during the demolition, a drainage pipe was damaged and it went unnoticed until after the cabinets were installed. My crawlspace stunk and it took about a month to get the smell out and repair the damaged pipes.
I am really happy with the quality of the cabinets and have tons of space in my kitchen now. FYI, I have a friend in the kitchen business who sells the appliances and does custom kitchen installations. His prices are about $60K for a good size kitchen like mine. He was very impressed with my kitchen that cost a fraction of what his would have cost me.