VMware ESXI boot partition

If you have not put the server in production, it would be better to just re-partition and reinstall VMWare EXi.  

The effort of reinstalling would be less as compared to trying to resize the partition.

I have  install VMware ESXi 6.7 in one of the Server with 150 SSD. it has take all 150 GB partition. Is there any way to reduce the ESXi partition & take out 100GB out of this. Please advice.

It would be easier to re-install.

Re-install ESXi on a USB Flash drive or SD Card/

and then use your  SSD for the datastore.

Yes i know, even i though of to re-install the whole server but is there anyother way to partion rather then re-install.

Yes, there is but it's not supported, you will have to use  partedUtil, or another third party utility partition utility.

The actual ESXi OS install should be small, and then it will use the reset of unused space as the datastore.

You are much better and recommended, re-installing on a SD card/USB flash drive and using all the SSD space as a datastore, later if you need to expand the datastore it will make like much easier, to seperate OS and Datastore on to, two different mediums.

ESXi is designed for SD/USB flash installation.

You can always backup existing configuration, and restore to you new installation later.