You might want to read this:
For the "A" version:
http://thewatchsite.com/files/Seiko%20T ... /7T32A.pdfAnd the slightly modified "B" version.
http://thewatchsite.com/files/Seiko%20T ... _7T42B.pdfI usually use an eye loupe, looking in the tiny holes of the back marked "push" and pull the crown until the indentation in the setting lever is visible. If I remember correctly, at the first click of the main crown and the second click of the alarm setting crown. Don't push too hard, the plastic movement is very fragile. If a crown fails to lock properly, you might have to disassemble the movement. (very scary, lots of little plastic gears)
Attaching the chrono seconds hand: push the hand on the axle using something like a wooden cocktail stick. Try to align it exactly with an index on the dial. You can adjust the zero reset position later, pull main crown to second click and push the top left button to align the minute hand and top right button to align seconds hand.
Good luck! I've been there....