Please help out newbie renaming issue

[homebro2000]

I want to rename some of my files, but not sure how I can accomplish.

Here is the items I am trying to rename

test1
test1 (track2)
test1 (track3)
test2
test2 (track2)
test2 (track3)
test2 (track4)

I want to rename above items so it would look like this below

test1 (track1)
test1 (track2)
test1 (track3)
test2 (track1)
test2 (track2)
test2 (track3)
test2 (track4)

How would I accomplish this?