How do I sell a business as a sole trader?
As a sole trader, you can only sell a business by selling the assets/IP/customer lists/etc. If you sell everything needed to continue to operate the business it will still be a sale of a going-concern.
As a company you have the choice to sell the business + assets or the shares in the company, which can sometimes make it easier to find a purchaser or obtain a higher price.
The difficulty with selling assets is that any contracts (leases, supplier agreements, etc.) will likely need consent to transfer to a different party, this mess is avoided where you are selling a Company.