Depends what was agreed and how good your solicitor is.
We claimed back costs for emptying the garage and disposing of a washing machine and fridge. Didn't have to do any chasing other than sending the solicitor a couple of photos of the garage. We got a cheque a few weeks later for the costs of a skip.
Similar here... When we moved 2 years ago got keys, went in, house was perfect, cleaned really well top to toe. Went in garage, not a single thing had been moved, large double garage piled high with a lifetime of junk...
Contacted solicitor and estate agent, explained the issue... Our solicitor contacted their solicitor and dealt with it. They offered to let me 'keep the useful tools they left for me'... erm, nope, its junk, I need it gone as I have to move MY tools, classic car etc into the garage!
Long story short, the people we bought the house from turned up (arranged) and spent 8 hrs a day over 2 days emptying the garage into their cars and taking it to the local tip (just up the road).
If it had been a few bits I wouldnt have minded and would just have taken it to the tip... But this was literally a lifetimes worth of junk.