First, go to www.imagesplitter.net and upload the picture you want to use for your tile project.
Then click on the Split Image tab at the top of the page, select the number of rows and column slices according to the number of tiles you want the image to be on. When you are ready, click the Split Image button to create your slices. Your sliced images will be downloaded and saved in a .zip file.
Go back to Symbaloo and your webmix. You can either start from scratch and create tile after tile or you can already have the tiles and links in place to simply substitute the tile images. Right click on the tile to access the edit menu and upload the first slice for your top left tile. (Important: Make sure to remember where you started the image selection in order to have all tiles aligned)
Make sure to select the area of the image you wish to crop and have inserted into the tile. Repeat this step for every slice you have and your new quasi-bigger tile is created within minutes!