At first, I was going to ignore this post.
However, I'm not going to ignore it.
First, I'm going to say use you're brain.
Second, I'm going to suggest how you use it by suggesting the following...
Third, ULX includes a ULX_README.TXT file which points to a tutorial describing how to add admins to Garry's mod, no matter what admin mod you use.
Fourth, That question has been asked hundreds of times in both this forum and on Facepunch Gmod forums... if you used the Search function of either site, I'm sure you could find the answer.
Fifth; We answer that question in this forums FAQs thread. (See also point four above)
Sixth; Somewhere on this site we even have a video (see # 4 again)
Seven; bah, if you can't find your answer by using step one and two, then I'm sure we can't help you. There are probably more that I've forgotten, but I'm 100% sure if you follow the tutorial mentioned in third point, you'll get admin access.