Firstly get two of your roof tiles and either two full battens or two offcuts of batten and place them onto the roof one above the other.
How to retile a roof.
Stripping the roof start at the top and strip and denail covering with felt thus keeping the rain from affecting the inside get a hammer tacker fix 3or4 in the centre of the felt then that allows you to roll it out yourself once you have done that install counter batten if it has a sarking board or if you have open rafter then measure out the roof to strike lines for batten gauge i come down inch n quater from apex then 12 inch up from the eaves min is 12 and i dont go any more than 13 for.
Next place your two tiles one on top of the other loose onto the battens without anything being fixed.
Place a pitchfork flat garden shovel or shingle scraper under the shingle.
Position the first.
You should have reinforced the frame of the roof earlier before.
The nails in the shingle should come up with the shingle when you pry it off.
Pry the shingle from the roof.
This is on its own a major job that can take days and require special tools.
Make sure the tile lugs are seated snuggly onto the top edges of the battens.
How to tile a roof if you would prefer to read how to tile a roof and see more help please visit this link unless you found this video via my website.
Remove old roofing if applicable.