The timetable has been released for choosing the next Tory leader: https://www.bbc.com/news/uk-politics-62129267
The whole process should take about 2 months, the same amount of time it took to confirm Boris Johnson as Theresa May's replacement. Nominations close on 12 July (today), followed by a week to decide the final two candidates. The UK should have its new PM confirmed by 5 September.
_________________
It is easy to go down into Hell;
Night and day, the gates of dark Death stand wide;
But to climb back again, to retrace one's steps to the upper air –
There's the rub, the task.
– Virgil, The Aeneid (Book VI)