Pruning pearl bush

I’ve just moved to a new house and there are a number of shrubs which are rather overgrown. There’s this pearl bush which had spectacular flowers earlier in the year. However it’s huge. It’s been trailed up a trellis but this is struggling to hold it up now. It’s about 2.5m high 3m wide and 1m deep. I know it doesn’t like hard pruning so am wondering what to do. Any thoughts? Thanks