Please follow this advice with your second child.
1. Take the diaper off the kid.
2. Do not buy or use pull-ups.
3. From the money you saved not buying pull-ups, buy cheap underwear. Allow the kid to choose the underwear him/herself.
4. Allow the kid to wear the underwear, or nothing (depending on where you are).
5. Use a potty, a toilet seat, or both. Place the potty (if using) wherever you or the kid feels it will be of most use. Move it wherever you/she/he wants to move it to. As often as you/they want.
6. Clean up the messes without fuss.
7. Learn to recognize the kid’s body language when peeing or pooping is imminent, and use words to encourage to go to the potty or toilet in time.
8. Use bribes. Or not. If you use them, you can call them motivators if it makes you feel better.
9. Bring with you, once the peeing is getting better, extra underwear, pants, socks, plastic bags, wet wipes and hand sanitizer wherever you go. (The bags are for placing the wet and or soiled clothing into.)
10. Prevail. Your kid will learn.
11. Adjust your rules, expectations, and hopes as often as you need.
12. Blog about it if it makes you feel better. A sense of humour will help maintain your sanity.