Ok this is very easy to do. I'll have a short version that condenses everything stated in the longer version afterward. This guide was found on xbox360achievements created by BOYCE.
SHORT VERSION
Hit Ichiro, then throw 2 passed balls. He will advance to 3rd. Walk Vidro (Mariners pinch ran for Vidro with Reed.) Then throw a high fastball until Ibanez tries to bunt. When he misses, run to the front of the plate and tag out Ichiro. BAM achievement unlocked.
Remember to put AI settings up for stealing, aggression, sac bunt, etc.
LONG VERSION
1. Go to the My 2K8 menu, and then go to Difficulty settings. Increase the AI's aggressiveness, steal success, steal 2nd, steal 3rd, squeeze bunt, etc. to full. Just make sure to max out the all the running stats for the AI.
2. Under the Management tab, go to the Roster menu and bring up the Boston Red Sox. Edit their catcher, Jason Varitek, to be 7' tall and 300 lbs, and increase his block plate and block pitch stats to full.
3. Set up a 1-inning (this is very, very important, as this will set up what will happen in step 6) exhibition game. Play as the Boston Red Sox (as the home team, which will allow you to pitch first) against the Seattle Mariners. Pitch with Josh Beckett, though any pitcher will do fine.
4. When the game loads, hit the first batter (Ichiro) with a pitch. The Mariners will bring in a pinch runner for Ichiro (as to why, I have no idea, considering Ichiro is the fastest player in the game) who will take his spot on first base. Then, allow the second batter to get a hit, and set it up so the pinch runner makes it to third base and the batter stays on first base.
5. When the next batter steps up to the plate, tap down on the d-pad, and then cycle the possible positions of your infielders until the third baseman and the shortstop are both playing in for a bunt.
6. Throw a fastball high and out of the strike-zone to this batter, and he will attempt to bunt it. Make sure he does not make contact with the ball. Your catcher will hold onto the ball, while the runner from third will charge home trying to score a run, as technically this first inning is the last inning of the game. Your catcher should tag him out, and the achievement should unlock.