Its a little tricky and not that easy to explain....

Fold the seats down and where it meets the car at the edges you will find something a little like my pic if you look straight down at it.
The red arrow points to a small metal arm that rotates over the fixing from the seat and this needs rotating away.
Once that is done the yellow arrow points to 2 small lugs that need to be pushed together, as you push them together will a little persuation you should be able to lift the back of the seat free.
To put back is just as simpledorp seat back into place make sure it clicks in then roaotae arm back over to secure!
Not the best explanation or pic but hopefully this well help!
If needed i can get a clearer pic side on of the above attachment on seat from my old cloth interior.

Fold the seats down and where it meets the car at the edges you will find something a little like my pic if you look straight down at it.
The red arrow points to a small metal arm that rotates over the fixing from the seat and this needs rotating away.
Once that is done the yellow arrow points to 2 small lugs that need to be pushed together, as you push them together will a little persuation you should be able to lift the back of the seat free.
To put back is just as simpledorp seat back into place make sure it clicks in then roaotae arm back over to secure!
Not the best explanation or pic but hopefully this well help!

If needed i can get a clearer pic side on of the above attachment on seat from my old cloth interior.