You'll need to edit the Ciphers field on the client ssl profile.
If you haven't edited that field, you'll have the 'DEFAULT' cipher stack for the BigIP version you're running.
If you want to get rid of DHE ciphers all together you can fill the Ciphers field with:
DEFAULT:!DHE
If you want to see which cipher suites you currently have vs. which ones will be left with a new Ciphers value just issue the following command from the bash shell:
tmm --clientciphers DEFAULT
tmm --clientciphers 'DEFAULT:!DHE'
V14:
https://support.f5.com/csp/article/K54125331
V11-V13:
https://support.f5.com/csp/article/K13156
V10:
https://support.f5.com/csp/article/K10262