Save the tiles

[zingo]

Is it possible to remove tiles without damaging them?

 

[HEM2121]

probably not

 

[lajsiiwan]

If they fit poorly, you can probably save most of them by prying gently with a crowbar.

 

[Jan-Å]

Crowbar sounds a bit large and uncontrolled, I would use hammers and chisels in different sizes, lengths, and widths. Even when you're not careful with old tiles, many tiles often come off whole and fine, so it shouldn't be a big problem if you take it slow and careful.
But Murphy's Law also says that a few will break, that's how it always is

 

[zingo]

OK, thanks
I thought there might be something you could 'apply' to the joints to make them more pliable.

 

[Bezt]

It's probably not the joints that are the worst because you can scoop them out, they're backed with adhesive and that can be fairly secure.

 

[Jan-Å]

OK, thanks
I thought there might be something you could 'brush on' the joints to make them more manageable.

Well, the joint doesn't have much significance. It's the tile adhesive and how well it has adhered to the tile that determines if the tile can be removed completely.

 

[lajsiiwan]

If it was made in the 50s, it's lungnan. You can almost take it with your hands but sometimes I've come across a fix that's stuck so securely. Completely impossible to remove it manually.