Pruning camelias japonica & Susanqua
how to prune a 7 ft tall camellia into shape of a tree?
Here are some articles that will help:
Pruning a large camellia into a single-trunk tree can be done, but it may be difficult depending on how it has grown so far. It can be easier to convert an overgrown camellia into a tree form with multiple trunks- you would still remove all the lower branches that come off the chosen trunks.
They can also be cut back severely, in case you want to effectively start again: