How does your Pokemon evolve in Pokemon mystery dungeon blue rescue team ds version how do you get into the hole to evolve?

There'll be a cut scene where you find out about the evolution cave from Snubbull when it evolves into Granbull. Your partner is always tagging along behind you, and you can't go into the cave to evolve until you're traveling solo. So from there you go back to base and down the path you usually take to access the dungeons, and your partner will ask if you want to be able to switch leaders.

( This will happen later in the game). Select "Yes", and all Pokemon on your rescue team other than yourself will return to their respective friend areas, including your partner. Now that you're alone you can return to Whiscash pond and go into the cave to evolve, or go to a friend area and switch leaders with another Pokemon on your team and put the rest on standby.

You can never access the evolution cave unless you're traveling by yourself, and you must meet the usual requirements for the Pokemon you want to evolve in order for it to work. For example, Charmander must be Level 16 to evolve into Charmeleon, and Pikachu can only evolve into Raichu when you have a Thunderstone in your bag. They'll ask if you want to use an item when you enter the evolution cave.