I just got my Model 18 delivered and have been assembling it. Got the front wheel on fine, and the kickstand, etc. But I can’t figure out how to attach the handlebars. I got the securing bolt and nut out from the stem, but if I put the handlebars in place then there’s no space to reach back in and put the bolt back in the hole. I tried removing the front panel to no avail. How do I access the bolt hole once the handlebars are in place?