Fabric tub chairs with non removeable covers - how to clean them?

[YourHandInMyHand]

I have 2 fabric tub chairs that are looking a bit worse for wear, how do I go about cleaning them? Don't wont to spoil them and have never had to clean anything similar before so I'm clueless.

I use the steam cleaner on mine..

We hired a carpet cleaner that had an upolstery attatchment

Hmm was hoping it wouldn't involve spendiness, might have to price up options...