Hey, I recently went through the trouble of fitting it myself, took about 40 mins and a nice cut to my finger....
Im not sure what style of viv u have so I will just tell you what I did with mine. On the top and bottom of the viv there were plastic strips that were about 1/4 inch off the glass, the lid snapped into these. I measured the distance of the glass surface between the top and bottom plastic pieces and then, with the background rolled up, marked out the same distance on the background roll. Then I took a large exacto knife and cut the rolled up background so the roll was as long as the glass it needed to cover. You really need to cut carefully and basically saw through it with the knife:
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background roll
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Taping it in place is a little tricky and if you have some help is much easier. I had the GF hold it in place as I lined up the backdrop, I then lined up the end of the roll with the front glass pane on the viv and taped that end to the glass. I used clear scotch tape so it was almost impossible to see the tape. After the first end was taped I basically worked my way along the backdrop, pulling it tight and making sure its where it needs to be as I taped it to the viv. I taped the backdrop to the plastic strip, I guess if your viv is just flat glass like a fish tank you could either leave about a half inch of glass to tape it too or wrap the tape around the bottom and top of the viv. Once I taped my way to the other side of the viv I had my helper pull the remaining backdrop tight and I ran the exacto knife along the edge where it needed to end. Once that cut was made I taped it like the other side. Hope that helps, it worked out very well for me. If you have any questions feel free to PM me
