To open the W3, all needed is a guitar pick, as usual. I was hoping to replace the 32GB SSD with a 128GB one. As you can see, unfortunately and to be expected at the price, there is no SSD module:
The 32GB storage is soldered on the board, underneath the right side, a Samsung KLMBG4GE4A-A001 eMMC memory. According to Samsung's this page, it is not the faster ones in this series, which is, again, to be expected for the price.