Once you have PikaTimer up, just set Calibrated Delay to 490, Wanted Delay to 2407 (the delay for Snorlax), Calibrated Seconds to 14, and Wanted Seconds to 50. Click Create Timer and you should be ready to start.
Set your DS date, and get the clock ready. Get the clock set to the same time as Seed to Time says. Since PikaTimer says to set it 1 minute before, set the clock to 08:03 and get ready to press "OK" on the clock to set it. At the same time you press OK, hit your space bar and PikaTimer will start.
Start your game up while the first timer is running. Exactly when it hits 0, soft reset. Then press A quickly to get to the Continue screen. When the second timer hits 0, press A on the Continue screen to enter the game.
You can then call Elm to check what delay you actually hit. You will probably be off quite a bit for the first few tries, but PikaTimer has an Update option, so you can adjust pretty easily. Good luck, I'm pretty tired, so I'm going to sleep.