Hi Novie, applying for indefinite leave to enter is just like applying for a normal settlement visa outside UK.
I believe i sent you a link on your other thread on where to look for a start.
Anyway, here's more of it...Good luck!!

https://www.gov.uk/search?q=settleme...rom+outside+uk
https://www.gov.uk/apply-uk-visa
https://www.gov.uk/healthcare-immigr...ou-need-to-pay