Bit of a while since I grew them but they'll take pretty much any trimming you need to do. Just cut a few inches above buds/branching points.
Disentangling is probably a good first step to see if there's any unhealthy bits & to thin for good air circulation. You didn't say where they're planted but if you want sideways growth I think you can turn down long shoots to make them branch like you would with a climbing rose. Any unhealthy bits can be trimmed at any time of year.
Feed with a balanced or high nitrogen fertiliser now & then something like Tomorite when you anticipate or see the first flower buds

this is what the rhs says:
https://www.rhs.org.uk/advice/profile?PID=295

this is the section on pruning etc.

Pruning and training

Although Passiflora is a self-clinging tendril climber, it benefits from fan-training, which produces a more attractive plant than if left alone to scramble. After planting, cut back growing tips of all shoots to encourage branching from the base. For a step-by-step guide to fan training against a wall or fence, see our page on training and pruning climbers on first planting.

Tie main framework shoots in along the horizontal to allow flowering shoots to hang down. Once established prune in spring to shorten overlong shoots and remove any frost damage. Just after flowering, shorten trailing flowered sideshoots to a couple of buds from the main fan framework. Repeat annually.

If your passion flower is overgrown or badly frost-damaged, carry out renovation pruning in spring by cutting back the stems to 30-60cm (1-2ft) from soil level. Cut to a bud or side shoot wherever possible. The plant will respond by sending out lots of new green shoots. These will need thinning out and formative training. Flowering will be reduced for a year or two.