aquadart shower doors?

I have 2 x Aquadart Oslo OWLC/7 inward opening doors fitted in 1995. The LHS inward opening door no longer opens so I am forced to step into the shower using the RHS!. I have emailed Aquadart twice and brought in a plumber, without success. Can anyone give advice as to how I can make the LHS inward opening door OPEN? I have looked for a YouTube video but can't find anything. TIA