For the hull, I used the handgrenade pretty much straight out of the package. I removed the squirter handle and the cap that inserts in the water well. Then, once again, I raided the bits box to get suitable spaceship 'looking' parts.
The exhaust is a pony bead glued to a goblin shield. The bridge is the front end of a Space Marine bolter. The laser port is a seed bead. The top tower is the water well cap (turned around and covering the hole it went in.). And the two side fins are the muzzles off of Kroot rifles.
Once all the parts were glued on I sprayed the model with black primer. It is shown below next to a Firestorm Armada Sorylian frigate to give a sense of scale.
I then painted the model. I first gave the whole thing a coat of dark navy blue, then painted it with GW Shadow Gray. I then washed it with dark blue ink, and then drybrushed highlights with Duncan Decorator Acrylics Slate Blue. the final touches were to pick out some detail in metallics and then apply a couple decals. The results are shown below, again with a FA Sorylian frigate for scale.