This is possible to a degree by using in-game commands made available by enabling cheats. However, this command won't necessarily change a biome's blocks, but an area's biome classification.

In Minecraft, you can place and remove blocks using your bare hands or a designated tool based on the block's type of block.

Minecraft's command blocks allow players to automate console commands, but they are hard to find, so this guide shows how to get them.

How To Enter Commands In Minecraft In Minecraft, commands can be primarily used via the chatbox; at least most admins and players would want to feed them directly as text to see immediate action.

You can get a command block in your Minecraft Java or Bedrock world using cheats and a special chat command.

You can only get light blocks via the /give command so, er, don't expect to go mining for light. (If you need more details on Minecraft console commands, you can follow that link.) ...