Transition is primarily about meeting the changed and new requirements. As a laboratory the transition means you need to identifying any gaps in your policies, objectives, processes, procedures and records, to meet ISO 17025:2017 scope of requirements (see clause 8.1.1 and 8.2). Revising and or establishing the necessary documents is part of the process, however there is no prescribed way to number your documents.
Many laboratories that used the ISO 17025:2005 clause numbering have realigned the numbering with the new clauses. Others have not. What is important is link everything to the management system (clause 8.2.4), remove obsolete documents from use and make sure personnel have clear access to all the information necessary to comply with the new version.
Decide what will work best for your laboratory, practically, considering opportunities and risks of different ways you could go about the changes to your documentation.