Trying to replace back of Wifes Seiko after installing new battery. Darn thing won't stay snapped on. I'm afraid to put too much pressure. I can see some slight raised portions on the back that are suppose to snap in. Any secrets to doing this. Thanks Terry
The best kept secret is that most such watches need a press to put the back on.
However, Seiko and Citizen watches are so well made that it is possible to get the backs on without a press, if you have the experience.
The bench at work had damage where several watchmakers had used the wood of the bench to push against.
I couldn't advise anyone inexperienced in the technique. One would have to observe the actions in process and then attempt to emulate.
If you, the OP, has a Harbor Freight tool store close to you, you can pick up a watch press that should work. It's one of those odd items that HF will stock for watch-work. I have run across a few of those cases that are an absolute bear to get the back on without a press. The press isn't expensive, and has plastic dies that won't mar the case. You just need to pick the right size that contacts the bezel without pressing on the crystal and a press side that makes contact near the outside edge of the back.
Other than that you'll probably have to improvise with a pair of channel-locks or a vise where you can get leverage. The trick will be in figuring what to use that protects the watch as you apply pressure. As I said, the HF tool isn't expensive. Good luck.
Seiko is definitely not the hardest to get back on. Most will if not clip on with fingers then firmly hold the back on and press one edge against a side of a wooden bench. It should go on with an audible click.