If you meet all the requirements for working in Spain (residence and work permits), there are many ways to look for and find work. One of the most useful is the EURES network.
These companies take a commission from the employees' salaries. Many of the positions on offer do not require higher education qualifications. http://www.empresasdetrabajotemporal.net/pa%C3%ADs-vasco.html
The Press
On Sundays, some newspapers have situations vacant pages as a special supplement.
Job hunting on the Internet
There are many websites specialising in online job searching: