While Chris8875's guide is great, here is a better solution:
From October 7th, 2021 to now, you can no longer purchase/download any Jigsaw Jam packs along with Daily Challenges and regular Jigsaw downloadable puzzles. If you've purchased and downloaded the 2nd Jigsaw Jam pack prior the date listed above, you can play the 2nd Jigsaw Jam pack from directly the game. But if you purchased the 2nd Jigsaw Jam pack on both W8 and W10 but eventually upgraded the W8 version to the W10 version on W10 and decided to delete the W10 and download the W8 version through an APPXBundle file, here is the steps to import the 2nd Jigsaw Jam pack from W10 to W8 on W10:
NOTE: Check in your MS Store settings if you have auto update disabled for apps. If turned off, you're good to go. But turn it off if on. If you had it off when you installed the W8 version back in the day or through APPX file now, then you should have a playable W8 version.
1. Check your version of Microsoft Jigsaw. Open up the game and go to Awards > Achievements. If the achievements are pictured in a square, that's the Windows 8 version. But if the achievements are pictured as a rectangle, skip the next step.
2. If you have the Windows 8 version downloaded, create an APPX file of it or skip this step if you already have one. Here are steps how to do it:
https://docs.microsoft.com/en-us/windows/msix/package/create.... Once you are finished creating an MS Jigsaw (W8) appx file and stored it somewhere, update it to the W10 version through the MS Store.
3. Open File Explorer. In the search bar, type in this destination: C:\Users\(insert Windows username)\AppData\Local\Packages\Microsoft.MicrosoftJigsaw_8wekyb3d8bbwe\LocalState
4. There would be a folder called "DownloadedJamCollections". Copy it and paste it somewhere in your computer. You'll need this in a later step.
5. With an APPX file of the W8 version, delete MS Jigsaw with auto update settings turned off. Install the W8 APPX bundle and start the game. Exit out of the game after you sign into Xbox Live after the title screen.
6. Repeat step 6. This time, open up another File Explorer window with the destination where you pasted the DownloadedJamCollections folder with the 2nd Jigsaw Jam pack. Copy the folder and paste it to the other File Explorer window's destination, which should be this: C:\Users\(insert Windows username)\AppData\Local\Packages\Microsoft.MicrosoftJigsaw_8wekyb3d8bbwe\LocalState
7. Load up the W8 version and voilà.
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In order to get 3 stars in every Jigsaw Jaw pack from collections 1-2 (collection 1 is always there!), you'll have to work fast but try your best not to mess up your Accuracy and Speed Chains. If you keep messing up, then you won't have enough score to reach to all 3 stars in one pack. But you also have to be fast too to receive bonus points. A mouse is much easier since the piece moves with your mouse cursor, so you can just click near the puzzle pieces that seems a correct match instead of dragging the puzzle piece with your finger in touch-screen mode. Also, it'll ask you if you want to get extra time by watching an ad. Since the game's servers closed a while ago, you'll won't have to watch a single ad. With the extra time, you can save even more time trying to get 3 stars in one pack.
W10 = Windows 10
W8 = Windows 8