Most guitars come with a basic truss rod adjustment tool. While higher end instruments come with proper tools the ones that come with some budget guitars are not very handy if you have to do the job every other day. I use the Ball-End Hex Keys sold by . For Chinese and most Korean made guitars you will need the ‘Metric’ set.
The difference between adjusting a truss rod on one of these basses and other basses, is that the necks of these basses must be manually moved to the desired position and then the adjustment nuts are tightened (turned clockwise). If you have detuned any strings to remove the truss rod cover, retune the strings before adjusting the truss rods. You will need a straight thin walled 1/4" nut driver that will fit in the area of the truss rod adjustment nuts. You can get the tool from Rickenbacker if you desire or you can get one at a hardware store. Do not use a nut driver with a "T" handle nor should you attach a ratchet type handle, as these will allow you to use too much strength when you turn the nuts and possibly break the truss rods.
There is no need to be scared! You will not destroy your guitar by making truss rod adjustments. Just follow these basic rules. Make small adjustments, one quarter turn at the time. Allow time for the wood to follow the truss rod and settle before checking and also before making further adjustments. Remember to retune between adjustments as the tension of the neck will change the pitch of the strings. Stop and take it to a professional if you cannot easily turn the nut with the truss rod adjustment tool.
I will provide pictures of this technique soon. Some guys are comfortable with supporting the body between their legs while they do this procedure. I find that cumbersome. Some have been known to just support the neck just below the headstock on their leg, as they hold it by the headstock with one hand, letting the body hang free as they tighten down the truss rod adjustment nuts with the other hand (known as the "Quick and Dirty" method). Never try to tighten the nuts with more than the strength in your hand. If you use the strength of your arm to tighten them, you might break the truss rods. Never adjust the truss rod nuts of a 4000, 4001 or 4002 without following one of these procedures or the fingerboard might pop off the neck, sending you with your bass to a luthier to set the fingerboard on again. Never force an adjustment nut to turn. It might be stuck due to corrosion, or it may already be at the end of it's traveling distance of the threads on the truss rod.