My client is selling a commercial building, and today he received an offer submitted on the Commercial Contract-Improved Property (TAR 1801). He wants to accept the offer, but he asked me to strike out the paragraph that requires him to deliver estoppel certificates to the buyer because the only tenant occupying the property is on a month-to-month basis. Can I cross out part of the existing contract language?

Yes, but only as specifically directed by your client. Your client should put his instructions to you in writing and specifically state what changes he would like to be made. You should advise your client to contact an attorney for legal advice about the effect of striking out contract language.