Implementation steps are more or less the same in any case. After gaining the to management support, you need to define scope of the QMS and in your case it is only finance department, this will mean that your QMS will consider the rest of the company as external entity. Then you need to create all mandatory documents required by the standard and implement or update activities and processes in order to be compliant with requirements of the standard. For more information, see: Checklist of ISO 9001 implementation & certification steps https://advisera.com/9001academy/knowledgebase/checklist-of-iso-9001-implementation-certification-steps/
My company is oil analysis company and what i mean that what should i do at finance department for iso included also the whole company .also we don't do design clause should i put it at quality manual and also mentioned that clause is excluded
You can use this Free ISO 9001:2015 Gap Analysis Tool - https://advisera.com/9001academy/iso-9001-gap-analysis-tool/ and apply it to your department. First, it is better to check with your Quality Manager if the Finance Department is included in the Quality Management System. In many companies it is not included explicitly, in some companies participants for example while negotiating conditions with customers (clause 8.2).