customize nejm biblatex style

The biblatex NEJM style outputs author names as

Hall, LO, Kurt, MJ, Chen, JY, Cress, R, Hamilton, AS,

How to change to get output like

Hall LO, Kurt MJ, Chen JY, Cress R, Hamilton AS,

Meaning, how to remove comma after the family name?

• Even though I think I answered your question as intended, you may want to make your questions easier to answer in the future by providing a minimal working example (MWE/MWEB) that reproduces the current output and shows how you obtained it. Not all questions need an MWE to be answered, but some questions can't be properly answered without one and almost all questions benefit from an MWE if only to get people started more quickly and to make sure everyone is talking about the same thing. – moewe Jul 6 '18 at 12:37

The punctuation between the family and given name in family-given format is called \revsdnamepunct, to remove it just use

\documentclass[british]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{babel}
\usepackage{csquotes}

\usepackage[style=nejm, backend=biber]{biblatex}

Note that biblatex-nejm is about seven years old now and has not been updated for biblatex 3.3 (Biblatex 3.3 name formatting), so expect some rough edged and check if the output is as expected.