How do I fix this slipped roof tile?

[DIY10291]

I have a scaffold tower on rent for 2 more days from which I can (just about) reach this tile, so would like to fix it/pay some roofer to use my tower to fix it in the next 2 days.

As pictured, the bottom one of the large roof tiles between mine and my neighbour's house slipped down a bit a few months back. I tried to push it back into place but it slipped a bit more so I stopped. (But I can move the tower closer to it and should have better access from there). It looks like these large middle tiles were laid loose and mortared (a very long time ago). The one above it is also slightly lifted on the bottom side, which you can see in the picture.

Will pushing it back into place (with some pressure?) hold it a few more years? Or does it need more than that (mortaring?)? If so, should I be in a rush to find someone working on a local roof who will use my tower (it is currently at 3m height but can go to 4m), or would they want to use a ladder? Thanks

 

[datarebal]

It's more than just one. Looking at the old mortar you can see it no longer follows the tile contours. So the mortars moved too .

You will require 1 hip iron and some mortar to rebed from bottom up

 

[DIY10291]

It's more than just one. Looking at the old mortar you can see it no longer follows the tile contours. So the mortars moved too .

You will require 1 hip iron and some mortar to rebed from bottom up

Thanks. Do you think it would be a good plan to find someone working on a roof to do it in 15 mins using my tower? Or are they gonna need a ladder to get up there?

 

[datarebal]

I can't see the full length.
It's not 15 mins done properly

 

[DIY10291]

Ok. The other tiles all looked completely fine to me. I'm guessing yes, but is this one to get fixed urgently?

 

[Bosswhite]

Going by your picture the three ridge tiles shown need rebedding , and the hip iron is loose .