Um, to service the movement, you need to strip it down to its component parts.
For instance, here is my IWC GST on Master The Zigmeister's bench:
As you can see, that's some fiddly stuff right there.
When you reassemble it and oil it, using the 5 different required oils according to the oiling charts, you need to regulate it as well. Expect to pay 80 quid to have someone do an ETA 2824/2836 movement service in the UK. Chronographs are a little more, but don't expect anyone to touch the Chinese 7750 copies we use.
Or, you can do the Timezone course and learn to do your own ETA 2836. It's what I'm doing.