HELP!! How do I register my Ratman license?

[Glimia]

I accidentally skipped through the text saying how I can register the Ratman license and I dunno what to do now.

Can someone tell me how I can register it?

[ASCIIrider]

Go to weapon title merchan Zach in Roumen.
Click the Register License button
Drag your weapon to the slot on the top left
Drag the Ratman license to the slot under that
Click the icon across from where you dropped the license.