the first step for u is, "install SmartGit"
EDIT:
How to update fork by using TortoiseGit
See this album
Right-click your local fork, choose Settings On the left menu-list, click on Git -> Remote. (pic) Need to new remote for rAthena, just type 'rAthena' on remote textfield (it gives the remote name) and the URL is https://github.com/rathena/rathena.git (pic) Click Add New/Save. U will get new remote, named rAthena. (pic) After adding the new remote, there is prompt "Do you want to fetch remote branches from newly added remote?" Yes! (pic) Look at this picture, and OK
Wait until it done, you will see some it works, fetching from rAthena. (pic) If it's done, right-click on your local fork, choose Merge, Select remotes/rAthena/master on the Branch from (look at this picture), then OK. (pic) Wait until it done (it should be fast, it just merging ur local fork). (pic) Then u need to push it. Right-click on ur local repo, choose Push. On the Ref, select for local is ur master, and Remote is master too. And the Destination Remote is origin (it will be pointed to ur https://github.com/<username>rathena. OK. (pic) Wait it done, and look by browser on ur repo, it should be no different between urs and rAthena's repo. (pic)
*bump*