(Pictures comming soon)
What you will need:
Heidisql or an SQL program (im using navicat)
MYSql
Port forwarding knowledge
Step 1: Start by going to your router area on your web browser (type 192.168.1.1) and port forwarding port 3306 (check it by going to Open Port Check Tool)
(alternative if you know how to port forward using firewall) Step 1: Go to your firewall settings and click Exceptions, then add port name mysql port 3306 tcp (and make another named mysql2 3306 udp)
Step 2: open up navicat and double click your mysql connection. At the top you will see 'Manage Users' open that up and click add user.
Step 3: add the username of the person you want to connect (like their account name on your server) then their EXTERNAL IP in the Host area then type a password for them (probably their account password)
Step 4: after adding the account in navicat you will see a list of account names and to the right of the account names you will see check boxes. Click the account name on the left hand side you just created and click Select All then hit save. (This can be edited to your liking, after you hit select all i recommend removing Drop, Shutdown, Lock Tables, Delete and Grant. This prevents future damages to the server)
Send the person the info for the mysql program and let them edit as they like.
WARNING: ONLY DO THIS FOR SOMEONE YOU TRUST!
If you do this without being able to completely trust the person, they can seriously damage your server. USE EXTREME CAUTION