I used Glendas letter as a template for mine. The bit about sole custody no longer applies, my solicitor said it was out of date and made me change the wording. My ex's solicitor wasn't happy that it didn't say anything about my encouraging the upkeep of contact and she wanted to make me put contact times and dates in. I told her that was completely unreasonable and refused, I stood my ground when she tried the guilt trip and the intimidation thing and eventually got the whole thing signed and sealed.
Use Glenda's letter as a base, it's a great place to start but then get some legal advice as per your personal circumstances as well.
Good luck
