I did a little search and pythonocc seems to be only available on conda (There is a very very old version on pypi). You should be able to wire up the conda environment as shown in this thread to the Rhino Python 3 runtime and import the pythonocc package:
#! python 3
import os
import os.path as op
import sys
import ctypes
def connect_conda(conda_env_path: str):
"""Wire up search paths to conda environment
Args:
conda_env_path (str): absolute root path of conda environment
"""
# add the paths of site-packages in conda environment so packages can be found e.g. compas
sys.path.append(op.join(conda_env_path, r"Lib\site-packages"))
# tell python where it can find dlls. this is required to find all other .dll files that
# are installed as part of the other packages in the conda environment e.g. fblas
os.add_dll_directory(op.join(conda_env_path, r'Library\bin'))
connect_conda(r'C:\Users\ein\.conda\envs\wood-dev')
import OCC
print(OCC)
See more information here: