I am due in September with baby #2 and we just did this with our 2 year old (26 months) literally 2 days ago. I skipped the toddler bed since it is no different than her crib size-wise, and if you have to put bed rails on the toddler bed, than it's still basically a crib.
So for the past 3 weeks, we have been talking A LOT about her getting a new room (moved from the smaller bedroom to the bigger bedroom), a new big girl bed, new carpeting,new paint color, etc. All we did was talk talk talk about her new big girl bed. She goes to an in-home daycare twice a week and by my mom's house once a week so what I believe coompletely helped us was having her start sleeping in a "big girl bed" by their houses. All kids obviously listen to other people a little bit better than they listen to their parents, so the sitter and my mom would talk to her before naptime and tell her "No standing in the big girl bed" and make her repeat it back to them, "No getting out of the big girl bed" and make her repeat it, and then they told her "When you are all done sleeping, you stay in your bed and you wait for me to come and get you out of your bed." Worked like a charm. She never once tried to get out, and when we got the bed here at home, it took her about 30 minutes to fall asleep for her nap, and 20 minutes at night, but she never tried to get out of her bed (My husband and I had the same talk with her the last 2 days), and last night she was asleep in 10 minutes.
So, I would suggest going right to a regular bed, talking a LOT about how great it is to get a big girl bed for a few weeks, get really pretty bedding or her favorite character bedding, and if possible, try naptimes somewhere else to start with. Good luck!