Update custom-svg-icons.md (#10999)

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docs/code-howtos/custom-svg-icons.md

@@ -23,7 +23,14 @@ Good icon design requires years of experience and cannot be covered here. Adapti
 
 ## Step 2. Packing the icons into a font
 
-Use the [IcoMoon](https://icomoon.io) tool for packing the icons. Create a new set and import _all_ icons. Rearrange them so that they have the same order as in `org.jabref.gui.JabRefMaterialDesignIcon`. This will avoid that you have to change the code points for the existing glyphs. In the settings for your icon set, set the _Grid_ to 24. This is important to get the correct spacing. The name of the font is `JabRefMaterialDesign`. When your icon-set is ready, select all of them and download the font-package.
+Use the [IcoMoon](https://icomoon.io) tool for packing the icons.
+
+1. Create a new set by importing the json file
+2. Next to the icons, click on the hamburger menu, chose "Import to Set" to add a new icon (it will be added to the front)
+Rearrange them so that they have the same order as in `org.jabref.gui.JabRefMaterialDesignIcon`. This will avoid that you have to change the code points for the existing glyphs. In the settings for your icon set, set the _Grid_ to 24. This is important to get the correct spacing. The name of the font is `JabRefMaterialDesign`.
+3. Next to the icons, click on the hamburger menu and click "Select all".
+4. Proceed with the font creating, set the font property name to `JabRefMaterialDesign`
+When your icon-set is ready, select all of them and download the font-package.
 
 ## Step 3. Replace the existing `JabRefMaterialDesign.ttf`