Things You'll Need
Instructions
Creating an Infinite Water Spring
Press "E" to open your character's inventory.
Click the pickaxe and drag it to one of the nine squares at the bottom of your inventory screen.
Press "E" again to close your inventory. Press the number that corresponds to the inventory square you put your pickaxe in. For example, if your pickaxe is in the first inventory square, you would press the "1" key to equip it.
Dig a 2-by-2 hole anywhere on the map. The closer it is to the lava you want to remove, the easier it will be to get rid of the lava.
Equip a bucket from your inventory the same way that you equipped the pickaxe.
Find a source of water and right-click on it with the bucket equipped to put water inside of your bucket.
Carry the water to the 2-by-2 hole you dug and right-click to dump the water into one corner of the hole.
Fill the opposite corner of the hole with water using the same process you got water for the first corner. Once you fill both corners, the water will fill the hole, and it will refill every time you gather water from it.
Removing Lava
Use the bucket to gather water from your infinite water spring.
Drop the water over top the lava to remove it. If the lava square is a source, the water will turn the lava into obsidian. If the lava is not a source block, it will turn into cobblestone.
Use your pickaxe to clear any cobblestone or obsidian that formed from water interacting with lava. You can mine obsidian only with a diamond pickaxe.