Here, in Scotland, you have to have some trousers on (5)
I believe the answer is:
troon
'here in scotland you have' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'have some trousers on' is the wordplay.
'have' becomes 'roon' (I am not sure about this - if you are sure you should believe this answer much more).
'some' suggests taking the first letters.
'on' is a charade indicator (letters next to each other).
The initial letter of 'trousers' is 't'.
'roon' put after 't' is 'TROON'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for troon that I've seen before include "Open home" , "West Scottish town with links" , "Coastal town of West Scotland" , "Clyde port" , "Ayrshire golf course" .)