It was my right hip that was replaced, and here is how to get into the driver's seat:
1. Put plastic yard bag on driver's seat for easy sliding and no "sticking".
2. Back up to seat and have seat adjusted way back and also lowered to sleeping level if possible (this gives you more space to get legs lifted in).
3. Lower your bottom to seat, hanging on to each side of door jamb for stability.
4. Lift both legs into car at the same time. I used my leg lifter on operated leg and this was so helpful.
5. Pull car door closed with dressing stick. This really helped me.
6. Move driver seat back to good driving position. Make sure you can easily reach the brake and gas pedals. This position might be different from the one that worked well before the surgery.
7. Put dressing stick and leg lifter on front passsenger seat.
Before getting into the driver's seat I folded the walker and put it in the back seat. Hang on to the side of the car to reach the driver door, and also when getting out and going to the back door of car to get out walker. (I assume you have a four door car like I do.)
All the above felt awkward for quite a while, but then got to be routine and "second nature".
I am still getting in and out of the driver's seat the same way. I am accustomed to it and it doesn't take extra time.
I of course no longer have to use the walker. Yay!