I need help from people who know about proxy voting

[PerplexedProxy]

I have completed all the paperwork/application to vote by proxy on behalf of someone who is abroad. It has to be a postal vote because their constituency is 300 miles away from me. All has been confirmed and I am their named proxy..
Their postal vote has arrived with me.
Do I fill it in as per their choice but adding my DOB and signature?
I have googled and all I can find is how to apply for a proxy vote.
There are no instructions on the postal vote form.
It is a big responsibility and I don't want to get it wrong.
TIA.

I have once had a postal proxy vote. I can't remember exactly what we had to do. My sister was my proxy, but she was ballot counting or something in her own constituency, so couldn't vote in person in mine. She doesn't seem to be speaking to me a the moment, so I probably won't get an answer on what she had to do. I do remember it was quite a difficult process and that's with her being involved with the process as an officer, so easier to ask people in the know.

Sorry this doesn't help...

I have got the official letter naming me as proxy and have received the voting form. I guess I will have to sign it as me, as I can hardly forge their signature. Maybe I will enclose the confirmation of proxy letter in the envelope. It is a pity that there isn't a proper proxy postal vote form, given that we have done so many letters, forms and phone calls already.

Not sure it has to be posted. The people I am proxy for did it all online ? Took less than a week.

Op, if you got a postal vote pack then you must have applied to vote by post on their behalf. You mark the ballot paper as the elector has instructed and it’s your details, your signature and your date of birth, that you put on the statement.

Thank you. This is what I have done. I just had a moment of doubt, but it does actually say on the back of the slip that it is a proxy vote, so all ok. I have posted it and hope it arrives ok.