Oh my. To remove the lens and lens board, slide the lens board sliders up and to the left (upper one) and down and to the left (lower one). Left is your left with the camera facing you. Oh my.
Originally Posted by chazz
To remove the lens and shutter from the lens board, remove (unscrew) the lens' rear cell (if and only if it prevents access to the retaining ring), unscrew the retaining ring, pull the lens/shutter assembly out of the board.
To remove the lens' cells from the shutter, unscrew them. If they won't unscrew (normal right-hand thread, turn counter-clockwise to undo), pressing the apparently stuck cell against a tire's sidewall and turning the shutter often works.
Which lenses can be used on a 4x5 Speed Graphic? There are two limits that matter a lot, one that matters little. The first is the lens minimum flange-to-film distance at infinity. If that distance is shorter than the camera's minimum flange to film distance the lens can't be focused to infinity on the camera. The 4x5 Pacemaker Speed Graphic's minimum flange to film distance is 66.7 mm. If that distance is longer than the camera's maximum flange to film distance ("maximum extension") the lens can't be focused on any subject. The 4x5 Pacemaker Speed Graphic's maximum extension is 317 mm.
Go to www.graflex.org and read the FAQs. Go to www.southbristolviews.com, find and read the manuals. Go stand in a corner for the rest of the day.