Hi
I've just finished the process for the school to apply for Foreign expert letter to get the Z visa. It's not a short or easy process, unless you pay a lot of money. Since I needed to do 3 certificates, and I'm in Dubai, I did mine using family and friends!
(Ps...since I'm in Dubai I had to get police clearance from here and attested from here too...if you are in UK you need to do it there)
Chinese Embassy in London only deals with walk in applications...no phone or post! But I worked out everything by myself using their website...look for legalisation.
Here's what I did from Dubai...if you are in uk or have family/friends who can help it will be cheaper to do it personally. If not you will have to contact a company that will do everything for you...just Google. They cost about £150 per certificate that needs doing.
Process...
Colour photocopy all certs.
Take, or have someone take for you, the copies and originals to a solicitor. Ask them to sign the copy to say he has seen the originals and the copy is a true copy. (I think there might be exact details about what they need to write on the FCO website). This should cost about £5 per cert. People will tell you you need them notarized...you don't. And to be notarized costs about £70 each cert!
I applied to have copies attested by the FCO in UK...its an online form Fill in details, pay, you get an email with pdf.
Put that pdf in the post with the copies and send to FCO...NO originals needed for any more attestation, they do everything on the copies.
Took less than a week to get them sent back to mum. They have a form stuck on the back now...hence why you don't want to use originals.
Now you have to hand deliver them to Chinese Embassy, or consulate office. They cannot be sent by post. First, Go online to Chinese Embassy in London and find the form for legalisation. Complete and check what you need to take...different if you are taking them or you have a friend do it. Pretty sure you need your passport, or a copy, If friend does it, they need passport. But check.
Go to embassy, give stuff in and collect about 3 days later...again....you have to go personally, or send a friend. They are only open for a few hours in the morning. You pay when you collect I seem to remember. Now you will have another sticker on the back with a lovely hologram...and you are done!
I was then told to send scans of all the docs to my school in Shanghai. And they seem to be working on the next stage. My school said the next stage can take several months, our deadline to get documents to them was mid March, so don't delay! Since later, you'll get a letter and still have to apply to the Chinese Embassy again to get the visa stamped in before you can go! LOL. I'm sure it will be worth it!
I had a nightmare trying to work out what to do, but once I decided on the way, it was relatively painless, especially as I have a friend in London so I sent everything to her to take to the Embassy! Total saviour!
Hope that helps.