Heres a free tip that you can add on your phone:

Step1. Turn the phone on and head to settings.
Step2. Head to settings.
Step3. Find and click "General"
Step4. click to "accessibility"
step5. Go down and find the topic "Physical & Motor"
step6 Click "Assistive Touch"
Step7 Turn "assistivetouch" ON and your done!

Hope you didn't have trouble, if you do PM me.

-Clown

ClownHead wrote Heres a free tip that you can add on your phone:

Step1. Turn the phone on and head to settings.
Step2. Head to settings.
Step3. Find and click "General"
Step4. click to "accessibility"
step5. Go down and find the topic "Physical & Motor"
step6 Click "Assistive Touch"
Step7 Turn "assistivetouch" ON and your done!

Hope you didn't have trouble, if you do PM me.

-Clown

I don't find this method very useful. My lock button used to be broke and I used that method. But later I fixed it by taking it apart and I liked taking it apart and fixing it a lot better than assistive touch. You can take it apart yourself (a bit risky) or pay someone to do it. (May cost you a bit). But it's worth it in the long run.

You could take it to Apple or another repair place, or if you just wanna temporarily fix it, use Assistive Touch or something like that. You could order the parts, and try to change it your self, but that's risky. I've had an iPhone break while replacing parts, so if you were to do it, be careful and figure out what you're doing before you start the process.

Honestly the best way to fix it is by opening up but if you don't feel comfortable doing that then you should take it to a repair shop. It shouldn't cost you more than 30 to fix it.