A track of the four drum beats on infinite loop
A volume control
A very gullible Dr Who fan
Some way of getting them to hear it (PA system, speakers, etc, just make sure they hear it where ever they go!)
A fog watch that can't be opened
Decent Skills with Lying or trickery
Step 1: Make sure everyone else who happens to hear the soundtrack, knows to pretend not to notice it.
Step 2: Start by playing the soundtrack while the victim sleeps if possible.
Step 3: Give them the fog watch saying that somebody gave it to you for them, and that they need to return to the way they were
Step 4: Start by playing the soundtrack very quietly, so it's just barely audible, and increase in volume until they are convinced that they're hearing the drums
Step 5: Drop a hint that they may be the Master hiding as a human from the time war as subtly as possible.
Step 6: Hope that all of your work will pay off with them thinking that they are the Master, and possibly going crazy.
Step 7: (if successful): Watch the magic happen :D
Author's Notes: Sorry about any remotely possible disappointment at my continued delays with releasing chapters on Maurice, encountered some writer's block, so to make up for it, I'm starting a series called 'Ways to Prank a Dr Who Fanatic' that I will release as frequently as possible.