A modular repair kit for repairing damaged pallet rack frames and a method of installation thereof which incudes modular elements that can be customized by mechanical process such as cutting, drilling and connecting, for example, by bolts, that avoids major modifications, such as welding, at the installation site. The modular repair kit utilizes a standard replacement post assembly that can be cut to fit into nearly any size gap that is created when the damaged portion of the pallet rack frame is removed. The remaining elements of the repair kit can then be customized to accommodate any size of the standard replacement post assembly.