Tips and tricks - Rebuilding

[Polyneikes]

Hello,

just starting playing factorio yesterday, and am trying to pick up what I can from the ingame Tips and Tricks messages.
Sounds to me like I can upgrade a building "onsite" - is that correct? Can anyone tell me how it is done?

[zytukin]

Any building can be upgraded (and downgraded) by using another of the same type by just placing it on top of the old one. When upgrading or downgrading a building, the new building will continue working as if nothing was changed, keeping the original recipe and contents that the old building had. The old building will end up in your inventory, or on the ground if your inventory is full.

Plop down the steel furnace right on top of the stone furnace to upgrade it.
Build red conveyors on top of yellow conveyors to upgrade it.
Build a fast inserter on top of a yellow inserter to upgrade it.
Build a Level 1 Assembler on top of a Level 3 Assembler to downgrade it.

[Smarty]

assemblers also keep their current recipe if you upgrade it