From the Super Mario Wiki
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The course features three Mini Peaches. It is one of the three courses (aside from Room R-5 and Room R-6) that need to be completed in order to unlock the option to replace the minis in most courses with Mini Peaches.
All three toys start on a platform at the top of the level, in the middle. They face away from the Goal Door, located just a little further to the left. After activation, the minis must be led with Pink Blocks into one of the Pipes under them, then transported to the other side using a Rotate Pipe. Once there, the player must use Pink Blocks again accordingly in order to escort the minis to the Goal Door further up.
Mini Mario Card
The Mini Mario Card is in the bottom right. The player must use Pink Blocks on the right to lead the Mini Peaches above some spikes and into a gap with a trail of Coins, at the base of which lies the card.