Replace Arduino Uno chip

Maybe a stupid way to do this, but I want using my Arduino Uno to program the onboard chip, then take that off to use in a custom project, and place a blank chip back for the next time...

Is that possible ?

Is that possible ?

Yes

Yup.

To program it directly via the serial port, the chip must have the bootloader installed; this can be installed using an ISP programmer (such as a USBAsp, or another Arduino running the Arduino as ISP sketch)

Of course, if you have such a programmer you don't actually need a bootloader anyway