Hi.
It’s easier to obtain NIE in the Spanish consulate by yourself, or sign a power of attorney and your lawyer could apply in Spain. Do not forget to include the copy of the Passport when you sign a power.
If you are in Spain, you have to go to the pólice, each police take more or less time to make an appointment.
I hope I have clarified your doubts, do not hesitate to contact me if yo have any further require.
Marisela Castro
info@mariselacastro.com