I changed the driver side light bulb in about 15 minutes on my 2006 Prius. Yes it was difficult, but it did not require any tools.
1. I removed the fuse box cover.
2. There is a spring covering the light bulb. You will notice the bottom of the light will move back, but the top stays fixed. I am not clear how I removed it, but it does unclip a swing toward the outside of the car. You need to have it out of the way to get it back in.
3. I pulled both the light and cable over the fuse box.
4. I put the new light in place, hold it with a paper towel to keep it clean from dirt or oil.
5. I put the light back in place and some how reattched the spring.