Unfortunately, iD does not support reordering relation members, so you’ll need to switch to JOSM for that. Here are two helpful English-language resources with step-by-step instructions and screenshots:

JOSM Wiki “Help/Relations”: https://josm.openstreetmap.de/wiki/Help/Relations

Help OpenStreetMap thread “Re-ordering / sorting ways in a relation”: https://help.openstreetmap.org/questions/8197/re-ordering-sorting-ways-in-a-relation

In JOSM, there’s a “Sort Members” button built into the Relation Editor that will automatically arrange all the ways so they follow the actual hiking path. Here’s how to do it:

Open your hiking relation

Select the relation tagged type=route and route=hiking (or route=foot) in JOSM.

Launch the Relation Editor

Press Ctrl + Shift + M, or go to Edit → Edit Relation.

Click “Sort Members”

In the Relation Editor window, find and click the Sort Members button (usually an icon with three horizontal lines and an arrow). JOSM will reorder all ways so they form a continuous walking path.

Save and upload your changes

Close the Relation Editor and press Ctrl + S (or click the save button) to commit the updated relation to the server.

For more details on corner cases—like circular loops, alternate branches, or disconnected segments—please refer to the full documentation linked above.

Hope this helps! Let me know if you run into any problems.