Question: How to delete text ?

Sir/Madam

My Version of MAPLE is 13.02

I have the following expression on my worksheet:

(63/8) ((cos(Θ))^5)[G,H,L,P,T,U]^5 -(35/4)((cos(Θ))^3)[G,H,L,P,T,U]^3 + (15/8)(cos(Θ))[G,H,L,P,T,U]

I do not need the factors of [G,H,L,P,T,U] and I want to delete them, but all my efforts in the past few hours are in vain. I have tried to highlight those expressions and then use the EDIT -> DELETE ELEMENT and/or just the delete key on my keyboard, and many other combinations but was unable to remove those expressions. I searched the HELP tab and the MAPLEPRIMES.COM but could not find an answer or a simple example. There are examples of how to enter many expressions, but they are not followed by simple examples of how to delete them.

Could you please give me a hint?

Thank you,

Moses Tenne