First, why would you want to do it? It's hard on synchros and gear forks not to mention gear teeth when you miss a shift.
Here's what you are trying to do when you shift an ordinary gear box with out the clutch; 1. match engine rpm to road speed for whatever gear you want to be in. 2. coordinate this with the correct pressure on the shifter so as to complete the shift while the drivetrain is unloaded.
I would post instructions on how to, but I can see kids grenading thier parents gearboxes trying it.
Here's a few clues to doing it. 1. Rpm and drivetrain loading are controlled with you right foot. 2. Pressure on the shifter must be correct and constant during the shift. 3. Upsifting is easier than downshifting. 4. Practice with someone elses car before trying it with your own