We have a few options.
Newly as of 2019, we are able to print up to 26" in one direction for PLA. If the part is still too large, or you prefer to 3D print in multiple pieces, we could edit your file to be split into several pieces with male/female parts for assembly. However, we are only able to split into straight lines along the XYZ axes.
If you'd prefer to split your file strategically to hide seamlines, you could edit your file and resend it to us. From there, we could add the male/female attachment points for assembly.
We are able to complete this for all the materials we offer. If you have any more questions or you'd like to consult about your project specifically, please contact us.