1. Click on the ''Edit'' botton 2. Copy ALL the code who appears 3. Create a new rentry (i recommend to open it in another page) 4. Past the code there 5. Full it with your info or your OC's info (or whatsoever) 6. And your rentry is done! :D
If you still don't know how to do it, you can acess these sites: https://rentry.co/what and/or https://rentry.co/how (you can also see tutorials on the internet too!)