Compost bin worms

[Lobworm]

I have this compost bin which I have been enthusiastically (but possibly misguidedly) filling for the last few months. It’s nearly full, but I don’t think it’s becoming compost.
It mostly has guinea pig hay& waste plus some garden trimmings and kitchen waste (no meat/fish) the odd bit of newspaper
I was thinking about buying some worms www.wigglywigglers.co.uk/products/composting-worms
Could I just drop them into the top of the bin? And then start a new heap maybe with worms in from the start. Or do I need to do something special?

We have a lightly insulated bin but it still takes 6-12 months to break down. It took about 18 months for it to settle down initially and for us to get the proportions right. For us it's kitchen waste with 2 adults and one pizza box a week in the summer, slightly less cardboard in the winter. We get enough very solid slightly clay-like black compost (but not smelly or slimey) for 2m² mulching about every 3-4 months from the bottom of it. We mix this into the soil or use straight as mulch because of how thick it is. Your hay is probably equivalent to pizza box, but it contains nitrogen from the pee so slightly less brown.

We aways found that the guinea pig waste took longer to compost than garden waste. Despite the copious wee and poo, it always seem dry and needed to be kept watered.
We also line our bin (made from old pallets) with polystyrene trays, eg pizza bases, to keep it warm.

Have you opened the door to see what’s happening at the bottom? The top will always be unrotted as it’s the most recent stuff