Install the Footmatic and Ghostscript packages, then restart your Mac. You will not be prompted to restart, but it is necessary before you can install the hpijs package. After the restart, install the hpijs package, and restart again. Now go to System Preferences » Print and Fax » Add Printer (click the '+' sign).
In the Add Printer window, select IP at the top of the window, and use the following settings:
- PROTOCOL: HP JetDirect-Socket
- ADDRESS: Obtain and enter the IP of the Time Capsule: 192.168.1.100, or whatever it actually is.
- QUEUE: leave blank
- NAME: HP Deskjet 2050
- LOCATION: Put whatever you'd like here.
- PRINT USING: HP Deskjet 2050 (the driver you installed)