Hi Shagufta - there are a few similar threads on the forum which have the guidance on how to apply to split a title.
This one explains the basics , just ignore the buyer/mortgage parts as it reads as if you are just renting/short let
I would add that splitting a large title isn't usually necessary if you are letting part. Many large properties are let or rented out for short periods of time and those lets/rents aren't registerable so there's no point splitting the title.