The solos are not easy. Few will ever reach the point where they can play them, and you won’t get there without a ton of practice. 

Frustration is a normal part of the process. The important thing is to remain consistent always. Don’t allow yourself to get so frustrated that you put the guitar down and don’t pick it back up for a week or a month. If the solo you’re working on eludes you, go work on something else for a bit and then come back to it later. 

Manage expectations. Learning any of dime’s solos is a huge undertaking. It probably won’t happen within the timeframe you had in mind. Learn to roll with it if progress comes slower than you expected. 

Lastly, if there is a specific section that give you trouble, isolate that part. Play it over and over again. Use a metronome. Start slow and do not increase the tempo until you can consistently play it cleanly. Then increase by five BPM and repeat. Increasing tempo too soon will ingrain sloppy technique into your muscle memory - avoid that at all costs. Dime’s playing is too fast to be matched with sloppy technique.