Uhm yea sure..
1: Go to the "User Control Panel". (Next to your profile at the banner above)
2: Scroll down and you'll see the "Your Profile" section. Like the image below:
3: Then click into "Change Signature".
4: From that onwards, it's pretty straight forward now. Just straight now copy or paste any image you like and edit it from Photoshop or any other editing programs.
OR
If you think everything there is too much of a hassle, you can just request a signature in the Main Forums > Imagery > Signature Request
Here's the website to there:
https://smgclan.net/forumdisplay.php?fid=126
Just follow the requirements there and make your request, easy! (No you don't need to pay them, it's a request so it might take some time for them to finish it, be patience!)
If there's anything else you're unfamiliar with, you can always ask the Staff Team. Eventually one of them will respond to you!
As always, stay frosty. Staff Team got your back.
Merry Christmas!
Staff Team