How can I upgrade my iPhone 4 gevey from 5.1.1 to 6.1.3.?

[iMore Question]

recently I upgraded my jb iPhone 4 (gevey) from 4.3.2 to 5.1.1 saving the baseband 4.10.01 via reds ow. Working well. Now Ssh blobs with Cydia are for 6.1.3 upgrade only. How to upgrade to 6.1.3 (jb or non jb) while saving baseband for gevey. Pls Help.

 

[kch50428]

Far as I know, the only thing you can update to now is 8.3