According to the rules for listening and to the physics of the world.
A sleeping character may make Listen checks at a -10 penalty. A successful check awakens the sleeper.
You should determine the maximum distance at which the sleeping guy, considering his high penalty to listen checks for being asleep, can possibly hear the offender approaching. Then you should start playing the approach round by round, rolling opposed checks until the guy who's looking for those shoes gets to them and scuttles away successfully.
Given the high penalty for sleeping, the fact that it's way easier to stack modifiers to move silently checks than to listen checks and the -1 penalty to listen checks for every 10ft of distance (which I'd personally count at the point of the thief's path closer to the victim for each round), this is probably going to be a pair of checks or even none if the thief has done his homework and invested in stealth items.
According to where the shoes are, a search check might be in order to find them. The character does not need to roll sleight of hand because there's nobody who could casually look the right way since the only opposition is asleep.
That said, most people who own magic shoes keep them in their magic bag and they sleep over it, exactly because of the high risks of theft happening.
Some also cast alarm in the general area where they sleep, but higher level magic might circumvent the spell, making it very ineffective
Picking locks is also probably noisy, but the rules say nothing about it. As a DM I would ask for a separate move silently check or impose a penalty on the lockpicking (with partial success in the form of "you open it, but it's noisy" - then make a fixed DC listen roll for the sleeper)
What happens if the thief is discovered may vary. If he's not in line of sight and stays still, the victim might just believe those noises were coming from somewhere else and go back sleeping, which might in turn have the thief in wait where someone else can see him, depending on the environment. (in a tavern, an NPC needing to pee; perched outside a housedoor, city guards)
"And now, for something completely different"
Of course that's how the rules make the world go round.
Most of the time, rolling multiple times and losing a lot of time determining distances and comparing modifiers before ever rolling is boring. It brings things to a crawl, it detracts time from the fun things you're doing at your table.
So, how could one rule it?
One move silently roll and maybe a spot and a sleight of hand roll are more than enough.
A single roll would be even better (and it's how some other games like the Burning Wheel do it). And if the thief is that much good, don't roll at all.
Even if you make sure failure has a price and you think the odds are fair, this is not a perfect solution. While multiple rolls introduce several failure points for the thief - and when the victim is a PC, maybe you want it - you're now arbitrarily deciding the needed number of rolls, diminishing the ability of your players to measure the difficulty of the task without your input.