I get quite a few queries about the Lidl greenhouse since I published my original article How to modify a Lidl greenhouse to make it more robust.
Similar walk-in greenhouses to that offered Lidls offering are available from other vendors. You will normally find the assembly instructions printed on a sheet of paper that should be contained within the box usually between the shelving. However, if it is not there or gets blown away when you take everything out of the box you will find the instructions here on their customer service site.
If you are looking for a replacement cover as they do disintegrate (UV light) or get damaged in time or can get blown away in strong winds (tie them down) then you can search on Amazon for a plastic cover greenhouse 143x73x195cm (Only Cover) and you will likely find it though it may not be available year round. If the dimensions of your greenhouse are smaller or larger then look for the appropriate size.
Note: I do not work for Lidl or any affiliated companies.
Yet another plant enthusiast 
Hello, Thank you for this post on Lidl’s pop up greenhouse. I followed your instructions to make the structure more robust. Unfortunately, I forgot to take off the cover before the winds came and it blew into the hedge. I now can’t find the instructions page. I tried the link you helpfully posted https://www.lidl-service.com/static/3595471/57256_GB_FI_SE_DK.pdf stays blank. Any ideas? I used Mozilla Firefox and Microsoft Edge. Neither found it. Many thanks
It seems they move it around. I link to an archive site: https://archive.is/hEEpG
Thanks for sharing this. Most useful. In the process of modding my unit. Do you know where you can get spare plastic joints/elbows etc for the frame
I lost the instructions
I seems they move the files around, here is the link: https://archive.is/hEEpG