The recent development of genetic lineage recorders, designed to register the genealogical history of cells using induced somatic mutations, has opened the possibility of reconstructing complete animal cell lineages. To reconstruct a cell lineage tree from a molecular recorder, it is crucial to use an appropriate reconstruction algorithm. Current approaches include algorithms specifically designed for cell lineage reconstruction and the repurposing of phylogenetic algorithms. These methods have, however, the same objective: to uncover the hierarchical relationships between cells and the sequence of cell divisions that have occurred during development. In this chapter, I will use the phylogenetic software FastTree to reconstruct a lineage tree, in a step-by-step manner, using data from a simulated CRISPR-Cas9 recorder. To ensure reproducibility, the code is presented as a Jupyter Notebook, available (together with the necessary input files) at https://github.com/irepansalvador/lineage_reconstruction_chapter .