How does this work when the videos were filmed in 60i? What's the process to make them 60p?
It's very easy, you have to film, edit and export on NTSC 720x480 29.97i (keep interlaced in every step, just don't deincerlace). You have to export a master video .dv or .avi or .mp4 but NTSC 720x480 29.97i. Same applies to PAL.
Then select NTSC profile on skatehype.com and wait for upload and encoding. Set video data and publish it.
Any question please ask
PD: There are also presets for 1080/720 30i to 1080/720 60p