Although crown lifting is a safer and less damaging method of pruning when compared to reducing the overall canopy size, it is still risky and must be well planned. It is best to be done as a gradual process, rather than all at once. If too many branches are removed at once, issues such as decay and discoloured wood could occur.
If your lower branches are very wide, it may be more beneficial to thin them initially rather than simply removing them - again, to avoid any decay. It’s vital to approach a qualified tree surgeon to help you to understand which decisions to make when it comes to any tree pruning, to avoid causing large amounts of decay or any structural problems.