Make a pictures as new

[koezegtboe]

Hello! This is my first post here and the tutorials here helped me a lot! But I have a problem and I couldn't find the right solution in the tutorials.
I have some pictures of Led Zeppelin I want to use for icons. the problem is the pictures are not really good quality. I would like to have them sharper. A way to make them look newer or better looking for icons.Can somebody help me with this problem?

Images and the rest




Thank you in advance!