Servicing DT Swiss 240 FRONT hub
The DT Swiss 240s front hub is a sealed bearing hub.  Service includes removing the endcaps, removing the bearing seals, regreasing the bearing cartridge, and then reversing the process. 

There are no special tools required.  The end caps are a friction fit, and, while they are tight, they will remove by hand.

If bearings are damaged, replace the entire cartridge. 

This does require special tools. Or at least, strongly recommend them.:)

One last thing:  If there is nothing wrong with the hub, no service is required.