1. First, we need to find WPS20 19 on the mobile phone, then update it to the latest version, and then click Open.

2. Open the WPS account, log in, and then click the application icon in the navigation bar at the bottom of the page.

3. We find the document processing option at the top of the page, and then click on the bottom right of the page to enter the document slimming.

4. After that, we can select the document we want to slim down from the list and do the corresponding operation.

Finally, we can click Start Slimming at the bottom of the page to compress the document, and then we can see that the document is compressed smaller.