What are the limits of encouragement and intimidation in inviting immodestly dressed female colleagues to Islam, what is the ruling of Islamic law on their clothing and behavior, and how can they be made to love Islam and be made to fear God's torment?

Calling to Allah Almighty has methods and approaches known to those who have studied and practiced them. There are many books on this topic available from specialized libraries. The general features of Da'wah (inviting to Islam) can be understood by referring to fatwas numbered (34110, 55302, 47419, 45233, 46375, 47403, 54984, 61142, 67637).

To know the ruling on a woman wearing trousers, refer to fatwa number (975). For the conditions of the Shari'ah hijab, refer to fatwas number (34336) and (32440). As for the regulations for working in mixed-gender environments, refer to fatwas number (34086) and (39606).

From these fatwas, the ruling on what you asked about becomes clear. In summary, the caller (Da'i) must possess good character, patience in the face of harm, tolerance for others' mistakes, and seek excuses for them.