How do I change from low power to high on a repeater channel on a BAOFENG GM-15 Pro?

[WSFD472]

 My unit has gotten on low power on my main repeater channel. For the life of me I can't figure how to get it back on high. I can not find anything in the manual.

[Socalgmrs]

Try pressing and holding the star key.  
 

also the best easiest way is to program in a computer.  

[Bogieboy01]

Not familiar with that particular radio, but have you looked for an option in the menu labeled TXP? On my ar5rm its option 02 on the menu.