what you want to do is disable seasons and leave just belchertown enabled. I would also clear out the target public_html directory and point your belchertown skin there.
In this example, I am disabling the seasons skin and writing the generated html to /home/weewx/public_html. Adjust your target html directory in both HTML_ROOT and in HTML_ROOT under [Belchertown]
# ===== START EXAMPLE =====
# Options for 'StdReport'
[StdReport]
# Where the skins reside, relative to WEEWX_ROOT
SKIN_ROOT = /etc/weewx/skins
# Where the generated reports should go, relative to WEEWX_ROOT
HTML_ROOT = /home/weewx/public_html
# The database binding indicates which data should be used in reports.
data_binding = wx_binding
# Whether to log a successful operation
log_success = True
# Whether to log an unsuccessful operation
log_failure = True
# Each of the following subsections defines a report that will be run.
# See the customizing guide to change the units, plot types and line
# colors, modify the fonts, display additional sensor data, and other
# customizations. Many of those changes can be made here by overriding
# parameters, or by modifying templates within the skin itself.
[[SeasonsReport]]
# The SeasonsReport uses the 'Seasons' skin, which contains the
# images, templates and plots for the report.
skin = Seasons
enable = False
[[Belchertown]]
skin = Belchertown
HTML_ROOT = /home/weewx/public_html
enable = true
# ===== END EXAMPLE =====