That would be the (only) right one. Before trying anything else, let the router fully boot up (wait 3-5 minutes to be on the safe side), press the reset button (if your device has one) for more than 5s (10s to be on the safe side), which should reset- and reboot your device, give it another 5 minutes for that and try ssh/ http again.
If that wasn't successful, go further through
at worst, look at the debricking info for your device.
installation instructions in the wiki clearly states:
The original firmware is based on OpenWrt so a sysupgrade image can be installed via the stock web GUI. Settings from the original firmware will be saved and restored on the new one, so a factory reset using the devices' reset button will be needed.